tests/uid*: use fchown* instead of chown*

Newer architectures have no chown syscall, so use fchown* syscalls
for testing printuid.

* tests/uid.test: Use fchown instead of chown.
* tests/uid.c: Test __NR_fchown instead of __NR_chown.
(main): Use __NR_fchown instead of __NR_chown.
* tests/uid32.c: Test __NR_fchown32 instead of __NR_chown32.
(main): Use __NR_fchown32 instead of __NR_chown32.
* tests/uid16.c: Test __NR_fchown and __NR_fchown32 instead
of __NR_chown and __NR_chown32.
(main): Use __NR_fchown instead of __NR_chown.
* tests/uid.awk: Update regexp.
diff --git a/tests/uid.test b/tests/uid.test
index f4cb8e7..d8b0261 100755
--- a/tests/uid.test
+++ b/tests/uid.test
@@ -17,7 +17,7 @@
 	fi
 }
 
-syscalls="getuid$s,setuid$s,getresuid$s,setreuid$s,setresuid$s,chown$s,getgroups$s"
+syscalls="getuid$s,setuid$s,getresuid$s,setreuid$s,setresuid$s,fchown$s,getgroups$s"
 args="-e trace=$syscalls"
 $STRACE -o "$LOG" $args ./"$uid"|| {
 	cat "$LOG"