Fix #2399 - duplication error with __v1model_version in v1model

[dush-t]

When you try to compile using p4c-bm2-ss --p4v 16 "foo.p4" -o "bar.json",
where foo.p4 includes v1model.p4, it throws this error -

/usr/local/share/p4c/p4include/v1model.p4(72): [--Werror=duplicate] error: __v1model_version duplicates __v1model_version.
const bit<32> __v1model_version = 20180101;
              ^^^^^^^^^^^^^^^^^
/usr/local/share/p4c/p4include/v1model.p4(66)
const bit<32> __v1model_version = 20180101;
              ^^^^^^^^^^^^^^^^^

This because __v1model_version is declared twice. This PR fixes that by, well, removing a line. Felt it would be better to just create a PR than creating an issue. This fixes issue #2399

[hesingh]

You don't need to include the json filename in double-quotes. I am using a p4c as latest as from yesterday and I cannot reproduce the issue. The P4 program I have used also includes v1model.p4.
See my test log below.

hemant@ubuntu:/tmp/p4c/build$ ./p4c-bm2-ss --std p4-16 ../testdata/p4_16_samples/v1model-special-ops-bmv2.p4 -o tmp.json
hemant@ubuntu:/tmp/p4c/build$ ./p4c-bm2-ss --version
././p4c-bm2-ss
Version 1.2.0 (SHA: 1659a2a1 BUILD: DEBUG)
hemant@ubuntu:/tmp/p4c/build$ ./p4c-bm2-ss --std p4-16 ../testdata/p4_16_samples/v1model-special-ops-bmv2.p4 -o "tmp.json"
hemant@ubuntu:/tmp/p4c/build$ 
hemant@ubuntu:/tmp/p4c/build$ ./p4c-bm2-ss --p4v 16 ../testdata/p4_16_samples/v1model-special-ops-bmv2.p4 -o "tmp.json"
hemant@ubuntu:/tmp/p4c/build$ 

[dush-t]

Update your p4 compiler again. The commit that introduced this issue was from 16 hours ago. Check then.

[hesingh]

After updating my p4c to latest, I can reproduce the issue, thanks.

[hesingh]

This checkin has caused the issue:

93f4598#diff-68d536ca6ecb3bfe9ddbb6d67f5a6207

Please wait for @mbudiu-vmw to review this PR code changes.

[ChrisDodd]

Looks like an auto-merge snafu

[mihaibudiu]

We should make sure we keep the one in the middle.

[dush-t]

After fixing this, please also update the p4c docker image, since it also contains this bug.

[mihaibudiu]

The docker image will be updated automatically after a while.