ShellPkg: Refine code by initializing local variable and adding ASSERT statement.

Add ASSERT statement and initialize local variable to make code more readable.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Qiu Shumin <shumin.qiu@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18689 6f19259b-4bc3-4df7-8a09-765794883524

ShellPkg/Application/Shell/ShellProtocol.c

@@ -1632,6 +1632,8 @@ EfiShellExecute(
   EFI_DEVICE_PATH_PROTOCOL  *DevPath;
   UINTN                     Size;
   EFI_STATUS                CalleeStatusCode;
+
+  CalleeStatusCode = EFI_SUCCESS;
   
   if ((PcdGet8(PcdShellSupportLevel) < 1)) {
     return (EFI_UNSUPPORTED);