fix: mount failure when mountOptions is empty

[cvvz]

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

[andyzhangx]

/lgtm
/kind bug

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx, cvvz

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Needs approval from an approver in each of these files:

• OWNERS [andyzhangx]

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[andyzhangx]

/cherrypick release-1.21

[andyzhangx]

/cherrypick release-1.20

[andyzhangx]

/cherrypick release-1.19

[k8s-infra-cherrypick-robot]

@andyzhangx: cannot checkout release-1.21: error checking out release-1.21: exit status 1. output: error: pathspec 'release-1.21' did not match any file(s) known to git

In response to this:

/cherrypick release-1.21

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[k8s-infra-cherrypick-robot]

@andyzhangx: #893 failed to apply on top of branch "release-1.20":

Applying: fix: trim duplicated spaces
Using index info to reconstruct a base tree...
M	pkg/blob/nodeserver.go
M	pkg/blobfuse-proxy/server/server.go
Falling back to patching base and 3-way merge...
Auto-merging pkg/blobfuse-proxy/server/server.go
CONFLICT (content): Merge conflict in pkg/blobfuse-proxy/server/server.go
Auto-merging pkg/blob/nodeserver.go
CONFLICT (content): Merge conflict in pkg/blob/nodeserver.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: trim duplicated spaces
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.20

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[k8s-infra-cherrypick-robot]

@andyzhangx: new pull request created: #895

In response to this:

/cherrypick release-1.19

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[andyzhangx]

/cherrypick release-1.21

[k8s-infra-cherrypick-robot]

@andyzhangx: new pull request created: #896

In response to this:

/cherrypick release-1.21

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[andyzhangx]

/cherrypick release-1.20

[k8s-infra-cherrypick-robot]

@andyzhangx: #893 failed to apply on top of branch "release-1.20":

Applying: fix: trim duplicated spaces
Using index info to reconstruct a base tree...
M	pkg/blob/nodeserver.go
M	pkg/blobfuse-proxy/server/server.go
Falling back to patching base and 3-way merge...
Auto-merging pkg/blobfuse-proxy/server/server.go
CONFLICT (content): Merge conflict in pkg/blobfuse-proxy/server/server.go
Auto-merging pkg/blob/nodeserver.go
CONFLICT (content): Merge conflict in pkg/blob/nodeserver.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 fix: trim duplicated spaces
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.20

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.