Very minor tweaks:
 - Remove (c) pseudosymbol.
 - Remove "All Rights Reserved."
 - Change "Google Inc." (no longer exists) to "Google LLC".

[git-generate]
echo '
,s/\(c\) //
,s/ All rights reserved.//
,s/Google Inc./Google LLC/
w
q
' | sam -d LICENSE

Change-Id: Ifc1b84adca131018a48ba47e741a682a0ed9bb49
Reviewed-on: https://go-review.googlesource.com/c/sync/+/598584
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>