disk-bind: pass slot and phynum from mpt2sas driver to sd_probe()

The mpt2sas driver could get slot and phynum from SAS-card, so we
could pass it to sd_probe() by sdev_gendev.

Signed-off-by: Robin Dong <sanbai@taobao.com>
disk-bind: call ext4_free_io_end() even with io error

If the ext4_convert_unwritten_extents() returns an error,
we no longer keep the end_io structure on the linked list.
This doesn't help, because it tends to lock up the file system and wedges
the system.  That's one way to call attention to the problem, but it
doesn't help the overall robustness of the system.

Part of the patch comes from http://kernel.opensuse.org/cgit/kernel/commit/?id=b82e384c7b

Signed-off-by: Robin Dong <sanbai@taobao.com>