Input: twl4030_keypad - fix potential NULL dereference in twl4030_kp_probe()

We should first check whether platform data is NULL or not, before
dereferencing it to get the keymap.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/twl4030_keypad.c

@@ -332,7 +332,7 @@ static int __devinit twl4030_kp_program(struct twl4030_keypad *kp)
 static int __devinit twl4030_kp_probe(struct platform_device *pdev)
 {
 	struct twl4030_keypad_data *pdata = pdev->dev.platform_data;
-	const struct matrix_keymap_data *keymap_data = pdata->keymap_data;
+	const struct matrix_keymap_data *keymap_data;
 	struct twl4030_keypad *kp;
 	struct input_dev *input;
 	u8 reg;
@@ -344,6 +344,8 @@ static int __devinit twl4030_kp_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	keymap_data = pdata->keymap_data;
+
 	kp = kzalloc(sizeof(*kp), GFP_KERNEL);
 	input = input_allocate_device();
 	if (!kp || !input) {