cifs: clean up length checks in check2ndT2

Thus spake David Howells:

The code that follows this:

  	remaining = total_data_size - data_in_this_rsp;
	if (remaining == 0)
		return 0;
	else if (remaining < 0) {

generates better code if you drop the 'remaining' variable and compare
the values directly.

Clean it up per his recommendation...
Reported-and-acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -248,15 +248,16 @@ static int check2ndT2(struct smb_hdr *pSMB, unsigned int maxBufSize)
 	total_data_size = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
 	data_in_this_rsp = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
 
-	remaining = total_data_size - data_in_this_rsp;
-
-	if (remaining == 0)
+	if (total_data_size == data_in_this_rsp)
 		return 0;
-	else if (remaining < 0) {
+	else if (total_data_size < data_in_this_rsp) {
 		cFYI(1, "total data %d smaller than data in frame %d",
 			total_data_size, data_in_this_rsp);
 		return -EINVAL;
-	} else {
+	}
+
+	remaining = total_data_size - data_in_this_rsp;
+
 	cFYI(1, "missing %d bytes from transact2, check next response",
 		remaining);
 	if (total_data_size > maxBufSize) {
@@ -265,7 +266,6 @@ static int check2ndT2(struct smb_hdr *pSMB, unsigned int maxBufSize)
 		return -EINVAL;
 	}
 	return remaining;
-	}
 }
 
 static int coalesce_t2(struct smb_hdr *psecond, struct smb_hdr *pTargetSMB)