Input: st-keyscan - fix potential zalloc NULL dereference

This patch fixes the following static checker warning:

drivers/input/keyboard/st-keyscan.c:156 keyscan_probe()
error: potential zalloc NULL dereference: 'keypad_data->input_dev'
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/st-keyscan.c

@@ -153,6 +153,8 @@ static int keyscan_probe(struct platform_device *pdev)
 
 	input_dev->id.bustype = BUS_HOST;
 
+	keypad_data->input_dev = input_dev;
+
 	error = keypad_matrix_key_parse_dt(keypad_data);
 	if (error)
 		return error;
@@ -168,8 +170,6 @@ static int keyscan_probe(struct platform_device *pdev)
 
 	input_set_drvdata(input_dev, keypad_data);
 
-	keypad_data->input_dev = input_dev;
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	keypad_data->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(keypad_data->base))