megaraid_sas : fix megasas_fire_cmd_fusion calling convention

The fusion HBAs don't really use the instance template like the other
variants, as it branches off at a much higher level.  So instead of
trying to squeeze megasas_fire_cmd_fusion into the wrong calling
convention call it locally with argument data types that match what
is passed.

[jejb: fix up 32 bit compile failure]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>