Shorten a variable access some using a cached value rather than

casting the input argument again, making the code more readable.

Reviewed by:	jhb
MFC after:	2 weeks
Approved by:	re (kib)

sys/dev/mfi/mfi.c

@@ -2132,8 +2132,7 @@ mfi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int flag, struct thread *td
 
 		if (ioc->mfi_sense_len) {
 			/* get user-space sense ptr then copy out sense */
-			bcopy(&((struct mfi_ioc_packet*)arg)
-			    ->mfi_frame.raw[ioc->mfi_sense_off],
+			bcopy(&ioc->mfi_frame.raw[ioc->mfi_sense_off],
 			    &sense_ptr.sense_ptr_data[0],
 			    sizeof(sense_ptr.sense_ptr_data));
 #ifdef __amd64__