media: flexcop-usb: clean up URB initialisation

Clean up URB initialisation somewhat by introducing a temporary variable
and separating declaration and non-trivial initialisation.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220822151456.27178-3-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/usb/b2c2/flexcop-usb.c

@@ -425,12 +425,14 @@ static void flexcop_usb_transfer_exit(struct flexcop_usb *fc_usb)
 
 static int flexcop_usb_transfer_init(struct flexcop_usb *fc_usb)
 {
-	u16 frame_size = le16_to_cpu(
-		fc_usb->uintf->cur_altsetting->endpoint[0].desc.wMaxPacketSize);
-	int bufsize = B2C2_USB_NUM_ISO_URB * B2C2_USB_FRAMES_PER_ISO *
-		frame_size, i, j, ret;
+	struct usb_host_interface *alt = fc_usb->uintf->cur_altsetting;
+	u16 frame_size;
+	int bufsize, i, j, ret;
 	int buffer_offset = 0;
 
+	frame_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
+	bufsize = B2C2_USB_NUM_ISO_URB * B2C2_USB_FRAMES_PER_ISO * frame_size;
+
 	deb_ts("creating %d iso-urbs with %d frames each of %d bytes size = %d.\n",
 	       B2C2_USB_NUM_ISO_URB,
 			B2C2_USB_FRAMES_PER_ISO, frame_size, bufsize);