Remove useless ES wrappers from the main IOS file

This removes wrappers for ES_DIVerify and ES::LoadWAD. They are not
really useful as we can simply call the ES function directly, and
it is actually somewhat confusing because both functions are static
and are not tied to a particular ES instance.

Source/Core/Core/Boot/Boot_BS2Emu.cpp

@@ -21,6 +21,7 @@
 #include "Core/HW/DVDInterface.h"
 #include "Core/HW/EXI/EXI_DeviceIPL.h"
 #include "Core/HW/Memmap.h"
+#include "Core/IOS/ES/ES.h"
 #include "Core/IOS/ES/Formats.h"
 #include "Core/IOS/IPC.h"
 #include "Core/PatchEngine.h"
@@ -406,7 +407,7 @@ bool CBoot::EmulatedBS2_Wii()
   DEBUG_LOG(BOOT, "Run iAppLoaderClose");
   RunFunction(iAppLoaderClose);
 
-  IOS::HLE::ES_DIVerify(tmd, DVDInterface::GetVolume().GetTicket());
+  IOS::HLE::Device::ES::DIVerify(tmd, DVDInterface::GetVolume().GetTicket());
 
   // return
   PC = PowerPC::ppcState.gpr[3];

Source/Core/Core/Boot/Boot_WiiWAD.cpp

@@ -11,6 +11,7 @@
 #include "Common/NandPaths.h"
 
 #include "Core/Boot/Boot.h"
+#include "Core/IOS/ES/ES.h"
 #include "Core/IOS/FS/FileIO.h"
 #include "Core/IOS/IPC.h"
 #include "Core/PatchEngine.h"
@@ -87,7 +88,7 @@ bool CBoot::Boot_WiiWAD(const std::string& _pFilename)
   if (!SetupWiiMemory(ContentLoader.GetTMD().GetIOSId()))
     return false;
 
-  IOS::HLE::SetDefaultContentFile(_pFilename);
+  IOS::HLE::Device::ES::LoadWAD(_pFilename);
   if (!IOS::HLE::BootstrapPPC(ContentLoader))
     return false;