scsi: megaraid_sas: Unique names for MSI-X vectors

Currently, MSI-X vectors name appears in /proc/interrupts is "megasas"
which is same for all the vectors. This patch provides a unique name for
all megaraid_sas controllers and their associated MSI-X interrupts.

Link: https://lore.kernel.org/r/20191007051828.12294-1-chandrakanth.patil@broadcom.com


Suggested-by: Konstantin Shalygin <k0ste@k0ste.ru>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>