mkfs: don't complain about overly large auto-detected log stripe units

mkfs: don't complain about overly large auto-detected log stripe units

If mkfs declines to apply what it thinks is an overly large data device
stripe unit to the log device, it should only log a message about that
if the lsunit parameter was actually supplied by the caller.  It should
not do that when the lsunit was autodetected from the block devices.

The cli parameters are zero-initialized in main and always have been.

Cc: <linux-xfs@vger.kernel.org> # v4.15.0
Fixes: 2f44b1b0e5adc4 ("mkfs: rework stripe calculations")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>