[SCSI] qla2xxx: Fix to allow to reset devices using sg interface (sg_reset).

Currently it is impossible to reset provided by Qlogic QLA2xxx driver
SCSI devices externally using corresponding sg devices, particularly via
sg_reset utility, because qla2xxx driver in qla2xxx_eh_device_reset()
function checks if the input scsi_cmnd has its private data (CMD_SP())
attached. Then the found pointer isn't used anywhere inside of
qla2xxx_eh_device_reset(). If the RESET request comes from sg device, it
doesn't have such private data.

The attached patch removes check for non-NULL CMD_SP() from
qla2xxx_eh_device_reset(), hence allows to reset QLA2xxx's devices using
corresponding sg devices.

AV: change applies to bus/host reset handlers as well.

Signed-off-by: Vladislav Bolkhovitin <vst@vlnb.net>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>