nvme: catch errors from nvme_configure_metadata()

nvme_configure_metadata() is issuing I/O, so we might incur an I/O
error which will cause the connection to be reset.
But in that case any further probing will race with reset and
cause UAF errors.
So return a status from nvme_configure_metadata() and abort
probing if there was an I/O error.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>