generic/081: Support old version of lvm

generic/081: Support old version of lvm

generic/081 and 108 fails in RHEL 6.3, like:
 # ./check generic/081
 FSTYP         -- btrfs
 PLATFORM      -- Linux/x86_64 kerneldev 4.2.0-rc5_HEAD_d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754_+
 MKFS_OPTIONS  -- /dev/vdd
 MOUNT_OPTIONS -- /dev/vdd /var/ltf/tester/scratch_mnt

 generic/081
 [failed, exit status 1] - output mismatch (see /var/lib/xfstests/results//generic/081.out.bad)
    --- tests/generic/081.out   2015-07-13 17:07:03.000000000 +0800
    +++ /var/lib/xfstests/results//generic/081.out.bad  2015-10-28 12:20:49.000000000 +0800
    @@ -1,2 +1,3 @@
     QA output created by 081
     Silence is golden
    +ERROR: checking status of /dev/mapper/vg_081-base_081: No such file or directory
 Ran: generic/081
 Failures: generic/081
 Failed 1 of 1 tests

Reason:
 Command of "lvm lvcreate --yes" failed because lvm in RHEL 6.3
 don't support '--yes' option.

Fix:
 Use yes pipe instead '--yes' option for lvm, to make the command
 support both new and old version of lvm.

Suggested-by: Dave Chinner <david@fromorbit.com>
Suggested-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>