[PATCH] IB/mthca: release mutex on doorbell alloc error path

Release mutex on error return path from mthca_alloc_db().

Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index e8f9347..46981d4 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -337,7 +337,8 @@
 		break;
 
 	default:
-		return -1;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	for (i = start; i != end; i += dir)