[V2] mtd: devices: docg3:- Handle return value of devm_ioremap.

[Arvind Yadav]

Here, If devm_ioremap will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.

Signed-off-by: Arvind Yadav <arvind.yadav...@gmail.com>
---
 drivers/mtd/devices/docg3.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index b833e6c..ffe3db0 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -2083,9 +2083,14 @@ static int __init docg3_probe(struct platform_device 
*pdev)
                dev_err(dev, "No I/O memory resource defined\n");
                return ret;
        }
-       base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
 
        ret = -ENOMEM;
+       base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
+       if (!base) {
+               dev_err(dev, "failed to map I/O memory\n");
+               return ret;
+       }
+
        cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
                               GFP_KERNEL);
        if (!cascade)
-- 
2.7.4