UBI: Call scan_all() with correct offset in error case

If we find an invalid fastmap we have to scan from the very beginning.
Otherwise we leak the first 64 PEBs.
Reported-and-tested-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

drivers/mtd/ubi/attach.c

@@ -1417,9 +1417,11 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
 				ai = alloc_ai("ubi_aeb_slab_cache2");
 				if (!ai)
 					return -ENOMEM;
-			}
 
-			err = scan_all(ubi, ai, UBI_FM_MAX_START);
+				err = scan_all(ubi, ai, 0);
+			} else {
+				err = scan_all(ubi, ai, UBI_FM_MAX_START);
+			}
 		}
 	}
 #else