scsi: lpfc: Resolve miscellaneous variable set but not used compiler warnings

The local variables called curr_data are incremented, but not actually used
for anything so they are removed.

The return value of lpfc_sli4_poll_eq is not used anywhere and is not
called outside of lpfc_sli.c.  Thus, its declaration is removed from
lpfc_crtn.h Also, lpfc_sli4_poll_eq's path argument is not used in the
routine so it is removed along with corresponding macros.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>