mtd: cfi: fix writebufsize initialization

When initializing mtd->writebufsize, we must take into account
possible flash chip interleaving. Wrong writebufsize initialization
caused UBIFS recovery issues resulting in unmountable UBIFS file
system on NOR flash partitions.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Guillaume LECERF <glecerf@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 4aaa88f..092aef1 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -455,7 +455,7 @@
 	mtd->flags   = MTD_CAP_NORFLASH;
 	mtd->name    = map->name;
 	mtd->writesize = 1;
-	mtd->writebufsize = 1 << cfi->cfiq->MaxBufWriteSize;
+	mtd->writebufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
 
 	mtd->reboot_notifier.notifier_call = cfi_intelext_reboot;