This patch avoids that the following compiler warning is reported while
compiling the lockdep unit tests:

include/liblockdep/rwlock.h: In function 'liblockdep_pthread_rwlock_trywlock':
include/liblockdep/rwlock.h:66:9: warning: implicit declaration of function 'pthread_rwlock_trywlock'; did you mean 'pthread_rwlock_trywrlock'? [-Wimplicit-function-declaration]
  return pthread_rwlock_trywlock(&lock->rwlock) == 0 ? 1 : 0;
         ^~~~~~~~~~~~~~~~~~~~~~~
         pthread_rwlock_trywrlock
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Fixes: 5a52c9b4 ("liblockdep: Add public headers for pthread_rwlock_t implementation")
Link: https://lkml.kernel.org/r/20181207011148.251812-6-bvanassche@acm.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>