MdeModulePkg SdBlockIoPei: Initialize 'SwitchResp' elements before using

The commit makes sure that the elements in array 'SwitchResp' get
initialized before being used.

Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
diff --git a/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdHci.c b/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdHci.c
index c251fbe..72efd56 100644
--- a/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdHci.c
+++ b/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdHci.c
@@ -2647,6 +2647,7 @@
   //

   // Get the supported bus speed from SWITCH cmd return data group #1.

   //

+  ZeroMem (SwitchResp, sizeof (SwitchResp));

   Status = SdPeimSwitch (Slot, 0xF, 0xF, 0xF, 0xF, FALSE, SwitchResp);

   if (EFI_ERROR (Status)) {

     return Status;