scsi: lpfc: Refactor cpu affinity assignment paths

During initialization, a lot of the same logic is used on MSI-X vector CPU
affinity assignment.

Create a lpfc_next_present_cpu() helper routine, and apply its usage for
refactoring purposes.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20230712180522.112722-10-justintee8345@gmail.com


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>