The virtual FC frame command exchanged with the VIOS is used for device
reset and command abort TMF as well as normally queued commands. When
initializing the ibmvfc_cmd there are several elements of the command that
are set the same way regardless of the command type.

Deduplicate code by moving these commonally set fields into a
initialization helper routine, namely ibmvfc_init_vfc_cmd().

Link: https://lore.kernel.org/r/20201118011104.296999-2-tyreld@linux.ibm.comAcked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>