restorecond: compatible with the use of EUID

The `EUID` does not exist in some shell environments. To ensure compatibility,
use `id -u` instead of `EUID` when `EUID` does not exist.

Signed-off-by: Huizhao Wang <wanghuizhao1@huawei.com>
Acked-by: Petr Lautrbach <lautrbach@redhat.com>

restorecond/restorecond.init

@@ -29,7 +29,11 @@ PATH=/sbin:/bin:/usr/bin:/usr/sbin
 [ -x /usr/sbin/selinuxenabled ] && /usr/sbin/selinuxenabled || exit 7
 
 # Check that we are root ... so non-root users stop here
-test $EUID = 0  || exit 4
+if [ $EUID  ]; then
+	test $EUID = 0  || exit 4
+else
+	test `id -u` = 0  || exit 4
+fi
 
 test -x /usr/sbin/restorecond  || exit 5
 test -f /etc/selinux/restorecond.conf  || exit 6