scsi: Fuse g_malloc(); memset() into g_malloc0()

Coccinelle semantic patch:

    @@
    expression LHS, SZ;
    @@
    -       LHS = g_malloc(SZ);
    -       memset(LHS, 0, SZ);
    +       LHS = g_malloc0(SZ);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/megasas.c

@@ -1018,8 +1018,7 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun,
     size_t len, resid;
 
     if (!cmd->iov_buf) {
-        cmd->iov_buf = g_malloc(dcmd_size);
-        memset(cmd->iov_buf, 0, dcmd_size);
+        cmd->iov_buf = g_malloc0(dcmd_size);
         info = cmd->iov_buf;
         info->inquiry_data[0] = 0x7f; /* Force PQual 0x3, PType 0x1f */
         info->vpd_page83[0] = 0x7f;
@@ -1221,8 +1220,7 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun,
     uint64_t ld_size;
 
     if (!cmd->iov_buf) {
-        cmd->iov_buf = g_malloc(dcmd_size);
-        memset(cmd->iov_buf, 0x0, dcmd_size);
+        cmd->iov_buf = g_malloc0(dcmd_size);
         info = cmd->iov_buf;
         megasas_setup_inquiry(cdb, 0x83, sizeof(info->vpd_page83));
         req = scsi_req_new(sdev, cmd->index, lun, cdb, cmd);