CIFS: cleanup min_t() cast in cifs_read()

Smatch complains that the cast to "int" in min_t() changes very large
values of current_read_size into negative values and so min_t()
could return the wrong value.  I removed the const as well, as that
doesn't do anything here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/file.c

@@ -1904,13 +1904,13 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
 	for (total_read = 0, current_offset = read_data;
 	     read_size > total_read;
 	     total_read += bytes_read, current_offset += bytes_read) {
-		current_read_size = min_t(const int, read_size - total_read,
+		current_read_size = min_t(uint, read_size - total_read,
 					  cifs_sb->rsize);
 		/* For windows me and 9x we do not want to request more
 		than it negotiated since it will refuse the read then */
 		if ((pTcon->ses) &&
 			!(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
-			current_read_size = min_t(const int, current_read_size,
+			current_read_size = min_t(uint, current_read_size,
 					CIFSMaxBufSize);
 		}
 		rc = -EAGAIN;