scsi: mpi3mr: Fix throttle_groups memory leak

Add a missing kfree().

Fixes: f10af057 ("scsi: mpi3mr: Resource Based Metering")
Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Link: https://lore.kernel.org/r/20230302234336.25456-2-thenzl@redhat.com


Acked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>