lpfc: mark functions as static in lpfc/lpfc_scsi.c

Mark functions as static in lpfc/lpfc_scsi.c because they are not used
outside this file.

This eliminates the following warnings in lpfc/lpfc_scsi.c:
drivers/scsi/lpfc/lpfc_scsi.c:299:1: warning: no previous prototype for ‘lpfc_change_queue_depth’ [-Wmissing-prototypes]
drivers/scsi/lpfc/lpfc_scsi.c:795:1: warning: no previous prototype for ‘lpfc_sli4_post_scsi_sgl_list’ [-Wmissing-prototypes]
drivers/scsi/lpfc/lpfc_scsi.c:3019:1: warning: no previous prototype for ‘lpfc_bg_crc’ [-Wmissing-prototypes]
drivers/scsi/lpfc/lpfc_scsi.c:3035:1: warning: no previous prototype for ‘lpfc_bg_csum’ [-Wmissing-prototypes]
drivers/scsi/lpfc/lpfc_scsi.c:3048:1: warning: no previous prototype for ‘lpfc_calc_bg_err’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: James Smart <james.smart@emulex.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>