dlm: fix basts for granted CW waiting PR/CW

The fix in commit 3650925893469ccb03dbcc6a440c5d363350f591 was addressing
the case of a granted PR lock with waiting PR and CW locks.  It's a
special case that requires forcing a CW bast.  However, that forced CW
bast was incorrectly applying to a second condition where the granted
lock was CW.  So, the holder of a CW lock could receive an extraneous CW
bast instead of a PR bast.  This fix narrows the original special case to
what was intended.

Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lock.c

@@ -1782,7 +1782,8 @@ static void grant_pending_locks(struct dlm_rsb *r)
 
 	list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
 		if (lkb->lkb_bastfn && lock_requires_bast(lkb, high, cw)) {
-			if (cw && high == DLM_LOCK_PR)
+			if (cw && high == DLM_LOCK_PR &&
+			    lkb->lkb_grmode == DLM_LOCK_PR)
 				queue_bast(r, lkb, DLM_LOCK_CW);
 			else
 				queue_bast(r, lkb, high);