xfstests: add _require_attrs

Add a new helper to check if extended attributes are supported.  It
errors out if any of the attr tools are not found, or if a filesystem
does not support setting attributes.

Remove the opencoded checks for the attr tools from various tests
now that we do them in common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>

187

@@ -51,11 +51,15 @@ _filter_version()
 # get standard environment, filters and checks
 . ./common.rc
 . ./common.filter
+. ./common.attr
 
 # real QA test starts here
-_require_scratch
 _supported_fs xfs
 _supported_os Linux
+
+_require_scratch
+_require_attrs
+
 rm -f $seq.full
 
 # lazysb and attr2 are in features2 and will require morebitsbit on