fchownat/fchownat01.c: cleanup

* Delete some useless commtents.
* Create fchownat.h to encapsulate fchownat(2)
* Use SAFE_* macros.
* Some cleanup.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
diff --git a/configure.ac b/configure.ac
index 89a86b3..ea6fa85 100644
--- a/configure.ac
+++ b/configure.ac
@@ -171,5 +171,6 @@
 LTP_CHECK_XFS_QUOTACTL
 LTP_CHECK_CLONE_SUPPORTS_7_ARGS
 LTP_CHECK_MKDIRAT
+LTP_CHECK_FCHOWNAT
 
 AC_OUTPUT