patch 9.0.1963: Configure script may not detect xattr

Problem:  Configure script may not detect xattr correctly
Solution: include sys/xattr instead of attr/xattr,
          make Test_write_with_xattr_support() test
          xattr feature correctly

This also applies to the Smack security feature, so change the include
and configure script for it as well.

closes: #13229

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
diff --git a/src/testdir/test_writefile.vim b/src/testdir/test_writefile.vim
index a54efa7..3b0164e 100644
--- a/src/testdir/test_writefile.vim
+++ b/src/testdir/test_writefile.vim
@@ -979,6 +979,7 @@
 
 func Test_write_with_xattr_support()
   CheckLinux
+  CheckFeature xattr
   CheckExecutable setfattr
 
   let contents = ["file with xattrs", "line two"]