BUG_ON() Conversion in fs/jffs2/

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

fs/jffs2/background.c

@@ -35,8 +35,7 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
 	pid_t pid;
 	int ret = 0;
 
-	if (c->gc_task)
-		BUG();
+	BUG_ON(c->gc_task);
 
 	init_completion(&c->gc_thread_start);
 	init_completion(&c->gc_thread_exit);