scsi: mpt3sas: Remove superfluous memset()

Fixes coccicheck warning:

./drivers/scsi/mpt3sas/mpt3sas_base.c:5247:16-34: WARNING: dma_alloc_coherent use in ioc -> request already zeroes out memory,  so memset is not needed

dma_alloc_coherent() already zeroes out memory so memset() is not needed.

Link: https://lore.kernel.org/r/1596079918-41115-4-git-send-email-liheng40@huawei.comSigned-off-by: Li Heng <liheng40@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -5259,7 +5259,6 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		_base_release_memory_pools(ioc);
 		goto retry_allocation;
 	}
-	memset(ioc->request, 0, sz);
 
 	if (retry_sz)
 		ioc_err(ioc, "request pool: dma_alloc_coherent succeed: hba_depth(%d), chains_per_io(%d), frame_sz(%d), total(%d kb)\n",