Input: imx_keypad - use the preferred form for passing a size of a struct

According to Documentation/CodingStyle - Chapter 14:

"The preferred form for passing a size of a struct is the following:

        p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts readability and
introduces an opportunity for a bug when the pointer variable type is changed
but the corresponding sizeof that is passed to a memory allocator is not."

So do it as recommended.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/imx_keypad.c

@@ -448,8 +448,7 @@ static int imx_keypad_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	keypad = devm_kzalloc(&pdev->dev, sizeof(struct imx_keypad),
-			      GFP_KERNEL);
+	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
 	if (!keypad) {
 		dev_err(&pdev->dev, "not enough memory for driver data\n");
 		return -ENOMEM;