Call SetLastError(0) to mute any errors after RenderDoc work

* Obviously not ideal, but better than passing spurious error codes
  back to the application where presumably it wasn't getting them
  before.

renderdoc/driver/gl/gl_hooks_win32.cpp

@@ -384,6 +384,8 @@ class OpenGLHook : LibraryHook
 
 			glhooks.GetDriver()->CreateContext(data, NULL, GetInitParamsForDC(dc), false, false);
 
+			SetLastError(0);
+
 			return ret;
 		}
 
@@ -391,6 +393,8 @@ class OpenGLHook : LibraryHook
 		{
 			glhooks.GetDriver()->DeleteContext(rc);
 
+			SetLastError(0);
+
 			return glhooks.wglDeleteContext_hook()(rc);
 		}
 
@@ -405,6 +409,8 @@ class OpenGLHook : LibraryHook
 
 			glhooks.GetDriver()->CreateContext(data, NULL, GetInitParamsForDC(dc), false, false);
 
+			SetLastError(0);
+
 			return ret;
 		}
 
@@ -480,6 +486,8 @@ class OpenGLHook : LibraryHook
 
 			glhooks.GetDriver()->CreateContext(data, hShareContext, GetInitParamsForDC(dc), core, true);
 
+			SetLastError(0);
+
 			return ret;
 		}
 		
@@ -516,6 +524,8 @@ class OpenGLHook : LibraryHook
 
 			glhooks.GetDriver()->ActivateContext(data);
 
+			SetLastError(0);
+
 			return ret;
 		}
 
@@ -531,6 +541,8 @@ class OpenGLHook : LibraryHook
 				glhooks.GetDriver()->WindowSize(w, r.right - r.left, r.bottom - r.top);
 
 				glhooks.GetDriver()->SwapBuffers(w);
+
+				SetLastError(0);
 			}
 
 			return glhooks.SwapBuffers_hook()(dc);

renderdoc/os/win32/win32_libentry.cpp

@@ -80,7 +80,11 @@ BOOL APIENTRY DllMain( HMODULE hModule,
 						)
 {
 	if(ul_reason_for_call == DLL_PROCESS_ATTACH)
-		return add_hooks();
+	{
+		BOOL ret = add_hooks();
+		SetLastError(0);
+		return ret;
+	}
 
 	return TRUE;
 }