extcon: max8997: Fix NULL pointer exception on missing pdata

commit dfee4111 upstream.

Fix NULL pointer exception when platform data is not supplied. The
driver dereferenced pdata pointer where it could be NULL.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 810d601fSigned-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/extcon/extcon-max8997.c

@@ -712,7 +712,7 @@ static int max8997_muic_probe(struct platform_device *pdev)
 		goto err_irq;
 	}
 
-	if (pdata->muic_pdata) {
+	if (pdata && pdata->muic_pdata) {
 		struct max8997_muic_platform_data *muic_pdata
 			= pdata->muic_pdata;