lockd: Fix stale nlmsvc_unlink_block comment

As of 5996a298da ("NLM: don't unlock on
cancel requests") we no longer unlock in this case, so the comment is no
longer accurate.

Thanks to Stuart Friedberg for pointing out the inconsistency.

Cc: Stuart Friedberg <sfriedberg@hp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/svclock.c

@@ -227,8 +227,7 @@ failed:
 }
 
 /*
- * Delete a block. If the lock was cancelled or the grant callback
- * failed, unlock is set to 1.
+ * Delete a block.
  * It is the caller's responsibility to check whether the file
  * can be closed hereafter.
  */