net/mlx4_core: Preserve pci_dev_data after __mlx4_remove_one()

pci_match_id() just match the static pci_device_id, which may return NULL if
someone binds the driver to a device manually using
/sys/bus/pci/drivers/.../new_id.

This patch wrap up a helper function __mlx4_remove_one() which does the tear
down function but preserve the drv_data. Functions like
mlx4_pci_err_detected() and mlx4_restart_one() will call this one with out
releasing drvdata.

Fixes: 97a5221f

 "net/mlx4_core: pass pci_device_id.driver_data to __mlx4_init_one during reset".

CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Amir Vadai <amirv@mellanox.com>
CC: Jack Morgenstein <jackm@dev.mellanox.co.il>
CC: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>