Extend testsuite/xattrs.test

First pach to extend xattr buffer makes rsync fail when copy files
without xattr such as fifo. Extend the test to ensure new patch work
as expected

Use checktee instead of checkit because gnu diff fails comparing fifos.

Author: Rodrigo OSORIO

testsuite/xattrs.test

@@ -259,5 +259,10 @@ checkit "$RSYNC -aiiX $XFILT . ../to" "$chkdir" "$todir"
 cd "$todir"
 xls file1 file2 | diff $diffopt "$scratchdir/xattrs.txt" -
 
+cd "$fromdir"
+rm -rf "$todir"
+mkfifo fifo1
+checktee "$RSYNC -avX --specials  $XFILT $dashH --super . '$chkdir/'" "$fromdir" "$chkdir"
+
 # The script would have aborted on error, so getting here means we've won.
 exit 0