xfs/292: fix format of expected message

xfs/292: fix format of expected message

In mkfs.xfs, it uses left-align and fixed width format when outputting
device name, so variable length of devicename makes different space's
number between "meta-data=devicename" and "isize". But in the expected
output, the space' number between them is fixed. This behavior often
results in the case failure. So fix the format of expected message.

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>