BUG_ON() Conversion in md/dm-path-selector.c

this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/md/dm-path-selector.c b/drivers/md/dm-path-selector.c
index a28c1c2..f10a0c8 100644
--- a/drivers/md/dm-path-selector.c
+++ b/drivers/md/dm-path-selector.c
@@ -86,8 +86,7 @@
 	if (--psi->use == 0)
 		module_put(psi->pst.module);
 
-	if (psi->use < 0)
-		BUG();
+	BUG_ON(psi->use < 0);
 
 out:
 	up_read(&_ps_lock);