scsi: megasas: initialise local configuration data buffer

When reading MegaRAID SAS controller configuration via MegaRAID
Firmware Interface(MFI) commands, routine megasas_dcmd_cfg_read
uses an uninitialised local data buffer. Initialise this buffer
to avoid stack information leakage.
Reported-by: NLi Qiang <liqiang6-s@360.cn>
Signed-off-by: NPrasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1464178304-12831-1-git-send-email-ppandit@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/megasas.c

@@ -1293,7 +1293,7 @@ static int megasas_dcmd_ld_get_info(MegasasState *s, MegasasCmd *cmd)
 
 static int megasas_dcmd_cfg_read(MegasasState *s, MegasasCmd *cmd)
 {
-    uint8_t data[4096];
+    uint8_t data[4096] = { 0 };
     struct mfi_config_data *info;
     int num_pd_disks = 0, array_offset, ld_offset;
     BusChild *kid;