block: mtip32xx: Remove call to memset after dma_alloc_coherent

In commit af7ddd8a
("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
dma_alloc_coherent has already zeroed the memory.
So memset is not needed.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.c

@@ -1577,7 +1577,6 @@ static int exec_drive_command(struct mtip_port *port, u8 *command,
 				ATA_SECT_SIZE * xfer_sz);
 			return -ENOMEM;
 		}
-		memset(buf, 0, ATA_SECT_SIZE * xfer_sz);
 	}
 
 	/* Build the FIS. */
@@ -2776,7 +2775,6 @@ static int mtip_dma_alloc(struct driver_data *dd)
 					&port->block1_dma, GFP_KERNEL);
 	if (!port->block1)
 		return -ENOMEM;
-	memset(port->block1, 0, BLOCK_DMA_ALLOC_SZ);
 
 	/* Allocate dma memory for command list */
 	port->command_list =
@@ -2789,7 +2787,6 @@ static int mtip_dma_alloc(struct driver_data *dd)
 		port->block1_dma = 0;
 		return -ENOMEM;
 	}
-	memset(port->command_list, 0, AHCI_CMD_TBL_SZ);
 
 	/* Setup all pointers into first DMA region */
 	port->rxfis         = port->block1 + AHCI_RX_FIS_OFFSET;
@@ -3529,8 +3526,6 @@ static int mtip_init_cmd(struct blk_mq_tag_set *set, struct request *rq,
 	if (!cmd->command)
 		return -ENOMEM;
 
-	memset(cmd->command, 0, CMD_DMA_ALLOC_SZ);
-
 	sg_init_table(cmd->sg, MTIP_MAX_SG);
 	return 0;
 }