ubifs: Remove unnecessary assignment

Assigning a value of a variable to itself is not useful.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/recovery.c

@@ -442,7 +442,6 @@ static void clean_buf(const struct ubifs_info *c, void **buf, int lnum,
 {
 	int empty_offs, pad_len;
 
-	lnum = lnum;
 	dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs);
 
 	ubifs_assert(!(*offs & 7));