scsi: lpfc: avoid an unused function warning

The only reference to lpfc_nvmet_replenish_context() is inside of an
disabled:

drivers/scsi/lpfc/lpfc_nvmet.c:1457:1: error: 'lpfc_nvmet_replenish_context' defined but not used [-Werror=unused-function]

This replaces the preprocessor conditional with a C condition, so the
compiler can see that the function is intentionally unused.

Fixes: 9a38e4f1c82f ("scsi: lpfc: Fix MRQ > 1 context list handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>