UBI: make vid_hdr non-static

Remove 'static' modifier from the 'vid_hdr' local variable. I do not know
how it slipped in, but this is a bug and will break UBI if someone attaches
2 UBI volumes at the same time.

Artem: amended teh commit message, added -stable.
Signed-off-by: Richard Weinberger <rw@linutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@kernel.org

drivers/mtd/ubi/vtbl.c

@@ -306,7 +306,7 @@ static int create_vtbl(struct ubi_device *ubi, struct ubi_scan_info *si,
 		       int copy, void *vtbl)
 {
 	int err, tries = 0;
-	static struct ubi_vid_hdr *vid_hdr;
+	struct ubi_vid_hdr *vid_hdr;
 	struct ubi_scan_leb *new_seb;
 
 	ubi_msg("create volume table (copy #%d)", copy + 1);