lpfc:Make the function lpfc_sli4_mbox_completions_pending static in order to comply...

lpfc:Make the function lpfc_sli4_mbox_completions_pending static in order to comply with function prototype

This makes the function lpfc_sli4_mbox_completion's definition
static now in order to comply with its prototype being also
declared as static too.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Reviewed-by: Sebastian Herbszt <herbszt@gmx.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>