7290 ZFS test suite needs to control what utilities it can run
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>

@@ -24,20 +24,20 @@
 # Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
 
 #
-# Copyright (c) 2013 by Delphix. All rights reserved.
+# Copyright (c) 2013, 2016 by Delphix. All rights reserved.
 #
 
 . $STF_SUITE/tests/functional/clean_mirror/default.cfg
 . $STF_SUITE/include/libtest.shlib
 
 verify_runnable "global"
 
-$DF -F zfs -h | $GREP "$TESTFS " >/dev/null
-[[ $? == 0 ]] && log_must $ZFS umount -f $TESTDIR
+df -F zfs -h | grep "$TESTFS " >/dev/null
+[[ $? == 0 ]] && log_must zfs umount -f $TESTDIR
 destroy_pool $TESTPOOL
 
 # recreate and destroy a zpool over the disks to restore the partitions to
 # normal
 if [[ -n $SINGLE_DISK ]]; then