internal/lockedfile/internal/filelock: fix aix build tag

aix uses the fnctl-based fallback implementation, not
flock, since its flock is susceptible to the problem
described at https://en.wikipedia.org/wiki/File_locking:
All fcntl locks associated with a file for a given
process are removed when any file descriptor for that file
is closed by that process.

Change-Id: I266bbf80c126765b302fbc713c47eb6000ec7be1
Reviewed-on: https://go-review.googlesource.com/c/tools/+/462657
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Alan Donovan <adonovan@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
diff --git a/internal/lockedfile/internal/filelock/filelock_other.go b/internal/lockedfile/internal/filelock/filelock_other.go
index 1333edf..a108915 100644
--- a/internal/lockedfile/internal/filelock/filelock_other.go
+++ b/internal/lockedfile/internal/filelock/filelock_other.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !(darwin || dragonfly || freebsd || illumos || linux || netbsd || openbsd) && !plan9 && !windows
-// +build !darwin,!dragonfly,!freebsd,!illumos,!linux,!netbsd,!openbsd,!plan9,!windows
+//go:build !(aix || darwin || dragonfly || freebsd || illumos || linux || netbsd || openbsd) && !plan9 && !windows
+// +build !aix,!darwin,!dragonfly,!freebsd,!illumos,!linux,!netbsd,!openbsd,!plan9,!windows
 
 package filelock