staging: lustre: lustre/ldlm: Fixed sparse warnings

Added __acquires / __releases sparse locking annotations
to lock_res_and_lock() and unlock_res_and_lock() functions
in l_lock.c, to fix below sparse warnings:

l_lock.c:47:22: warning: context imbalance in 'lock_res_and_lock' - wrong count at exit
l_lock.c:61:6: warning: context imbalance in 'unlock_res_and_lock' - unexpected unlock

Signed-off-by: Nayeemahmed Badebade <itachi.opsrc@gmail.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ldlm/l_lock.c

@@ -45,6 +45,8 @@
  * being an atomic operation.
  */
 struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock)
+				__acquires(&lock->l_lock)
+				__acquires(&lock->l_resource->lr_lock)
 {
 	spin_lock(&lock->l_lock);
 
@@ -59,6 +61,8 @@ EXPORT_SYMBOL(lock_res_and_lock);
  * Unlock a lock and its resource previously locked with lock_res_and_lock
  */
 void unlock_res_and_lock(struct ldlm_lock *lock)
+		__releases(&lock->l_resource->lr_lock)
+		__releases(&lock->l_lock)
 {
 	/* on server-side resource of lock doesn't change */
 	ldlm_clear_res_locked(lock);