scsi: lpfc: Fix sli4 adapter initialization with MSI

When forcing the use of MSI (vs MSI-X) the driver is crashing in
pci_irq_get_affinity.

The driver was not using the new pci_alloc_irq_vectors interface in the MSI
path.

Fix by using pci_alloc_irq_vectors() with PCI_RQ_MSI in the MSI path.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>