ubifs: remove unnecessary assignment

Assigning a value of a variable to itself is not useful. This
fixes a warning shown when using clang:
  warning: explicitly assigning value of variable of type 'int' to itself [-Wself-assign]
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/scan.c

@@ -175,7 +175,6 @@ struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
 void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 		    int lnum, int offs)
 {
-	lnum = lnum;
 	dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
 	ubifs_assert(offs % c->min_io_size == 0);