ZTS: Fix xattr_002_neg passing too soon

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11970

tests/zfs-tests/tests/functional/xattr/xattr_002_neg.ksh

@@ -57,6 +57,6 @@ for arg in ${args[*]}; do
 	# create a file
 	log_must touch $TESTDIR/myfile.$$
 	log_mustnot eval "cat $TESTDIR/myfile.$$ not-here.txt > /dev/null 2>&1"
-
-	log_pass "A read of a non-existent xattr fails"
 done
+
+log_pass "A read of a non-existent xattr fails"