[JFFS2] add cond_resched() when garbage collecting deletion dirent

We observe soft lockups when doing heavy test which creates
directory with a lot of direntries and deletes them. This
cycle is the reason fo this. Make it nicer and add cond_resched()
inside of it.
Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

fs/jffs2/gc.c

@@ -838,6 +838,8 @@ static int jffs2_garbage_collect_deletion_dirent(struct jffs2_sb_info *c, struct
 
 		for (raw = f->inocache->nodes; raw != (void *)f->inocache; raw = raw->next_in_ino) {
 
+			cond_resched();
+
 			/* We only care about obsolete ones */
 			if (!(ref_obsolete(raw)))
 				continue;