syscall: rm obsoleted comment

The comment being removed is no longer true as of CL 494916.

Change-Id: I4975866c58efb5c9c41db3640564ac7233f5840f
Reviewed-on: https://go-review.googlesource.com/c/go/+/542415
Auto-Submit: Ian Lance Taylor <[email protected]>
Reviewed-by: Tobias Klauser <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>
Run-TryBot: Kirill Kolyshkin <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: kolyshkin

src/syscall/flock_linux_32bit.go

@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// If you change the build tags here, see
-// internal/syscall/unix/fcntl_linux_32bit.go.
-
 //go:build (linux && 386) || (linux && arm) || (linux && mips) || (linux && mipsle)
 
 package syscall