[PATCH] Remove the last reference to rwlock_is_locked() macro.

Remove the lone, remaining reference to the long-deceased
rwlock_is_locked() macro.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>