scsi: megaraid_sas: struct MR_LD_VF_MAP: Replace 1-element arrays with flexible arrays

Replace the deprecated[1] use of a 1-element array in struct MR_LD_VF_MAP
with a modern flexible array.

No binary differences are present after this conversion.

Link: https://github.com/KSPP/linux/issues/79

 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20240711155823.work.778-kees@kernel.org


Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>