lib: Add SAFE_CHOWN()

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
utimes/utimes01.c: cleanup

Delete some useless comments.
Use some SAFE_* macros.
Move the test body from main() to utimes_verify().

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
utimes/utimes01.c: add EPERM and EROFS error value tests

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>