scsi: megaraid_sas: Use synchronize_irq in target reset case

Similar to task abort case, use synchronize_irq API in target reset
case.  Also, remove redundant call to megasas_complete_cmd_dpc_fusion
after calling megasas_sync_irqs in task abort case.

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>