[PATCH RESEND] mtd: onenand: onenand_base: check for region != NULL

[john.maxin at nokia.com]

Coverity has reported that inside the function "onenand_block_by_block_erase()" 
in onenand_base.c, we should add a check to prevent the incrementing of 
possible NULL value for "region"

Signed-off-by: Maxin B. John <john.maxin at nokia.com>
---
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 56a8b20..fd659f8 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -2424,7 +2424,7 @@ static int onenand_block_by_block_erase(struct mtd_info *mtd,
                len -= block_size;
                addr += block_size;

-               if (addr == region_end) {
+               if (region && addr == region_end) {
                        if (!len)
                                break;
                        region++;