HID: hid-uclogic-params: Invalid parameter check in uclogic_params_frame_init_v1_buttonpad

The function performs a check on the hdev input parameters, however, it
is used before the check.

Initialize the udev variable after the sanity check to avoid a
possible NULL pointer dereference.

Fixes: 9614219e ("HID: uclogic: Extract tablet parameter discovery into a module")
Addresses-Coverity-ID: 1443763 ("Null pointer dereference")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-uclogic-params.c

@@ -452,7 +452,7 @@ static int uclogic_params_frame_init_v1_buttonpad(
 {
 	int rc;
 	bool found = false;
-	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
+	struct usb_device *usb_dev;
 	char *str_buf = NULL;
 	const size_t str_len = 16;
 
@@ -462,6 +462,8 @@ static int uclogic_params_frame_init_v1_buttonpad(
 		goto cleanup;
 	}
 
+	usb_dev = hid_to_usb_dev(hdev);
+
 	/*
 	 * Enable generic button mode
 	 */