xfs: call roundup_64() to calculate the min_logblks

Replace roundup() with roundup_64() as we calculate min_logblks
with 64-bit divisions.  Hence, call roundup() will cause the
following error while compiling a 32-bit kernel:

fs/built-in.o: In function `xfs_log_calc_minimum_size':
fs/xfs/xfs_log_rlimit.c:140: undefined reference to `__udivdi3'
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Dave Chinner <dchinner@redhat.com>
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/xfs_log_rlimit.c

@@ -136,10 +136,12 @@ xfs_log_calc_minimum_size(
 	 * Also, the log size should be a multiple of the log stripe unit, round
 	 * it up to lsunit boundary if lsunit is specified.
 	 */
-	if (lsunit)
-		min_logblks = roundup(BTOBB(max_logres), lsunit) + 2 * lsunit;
-	else
+	if (lsunit) {
+		min_logblks = roundup_64(BTOBB(max_logres), lsunit) +
+			      2 * lsunit;
+	} else
 		min_logblks = BTOBB(max_logres) + 2 * BBSIZE;
 	min_logblks *= XFS_MIN_LOG_FACTOR;
+
 	return XFS_BB_TO_FSB(mp, min_logblks);
 }