ALSA: usb: fcp: Use USB API functions rather than constants

Use the function usb_endpoint_num() rather than constants.

The Coccinelle semantic patch is as follows:

@@ struct usb_endpoint_descriptor *epd; @@

- (epd->bEndpointAddress & \(USB_ENDPOINT_NUMBER_MASK\|0x0f\))
+ usb_endpoint_num(epd)

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Link: https://patch.msgid.link/20250516070938.12520-1-nichen@iscas.ac.cn
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Author: Chen Ni

sound/usb/fcp.c

@@ -1092,8 +1092,7 @@ static int fcp_find_fc_interface(struct usb_mixer_interface *mixer)
 
 		epd = get_endpoint(intf->altsetting, 0);
 		private->bInterfaceNumber = desc->bInterfaceNumber;
-		private->bEndpointAddress = epd->bEndpointAddress &
-			USB_ENDPOINT_NUMBER_MASK;
+		private->bEndpointAddress = usb_endpoint_num(epd);
 		private->wMaxPacketSize = le16_to_cpu(epd->wMaxPacketSize);
 		private->bInterval = epd->bInterval;
 		return 0;