usb: storage: alauda: Remove set but unchecked variable

The return value of alauda_get_media_status() hasn't been checked
since the driver's inception back in 2005.  If nothing have gone
wrong/been detected until this point, it's probably safe to just
remove the variable.

Fixes the following W=1 kernel build warning(s):

 drivers/usb/storage/alauda.c: In function ‘alauda_check_media’:
 drivers/usb/storage/alauda.c:456:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
 456 | int rc;
 | ^~

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: usb-storage@lists.one-eyed-alien.net
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200703174148.2749969-20-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/storage/alauda.c

@@ -453,9 +453,8 @@ static int alauda_check_media(struct us_data *us)
 {
 	struct alauda_info *info = (struct alauda_info *) us->extra;
 	unsigned char status[2];
-	int rc;
 
-	rc = alauda_get_media_status(us, status);
+	alauda_get_media_status(us, status);
 
 	/* Check for no media or door open */
 	if ((status[0] & 0x80) || ((status[0] & 0x1F) == 0x10)