Abort early when hitting unexpected EOF in AC3D loader

Without this the code will try to loop through the specified number
of surfaces which could be very large even though none will succeed.

code/ACLoader.cpp

@@ -349,8 +349,7 @@ void AC3DImporter::LoadObjectSection(std::vector<Object>& objects)
                 {
                     if(!GetNextLine())
                     {
-                        DefaultLogger::get()->error("AC3D: Unexpected EOF: surface is incomplete");
-                        break;
+                        throw DeadlyImportError("AC3D: Unexpected EOF: surface is incomplete");
                     }
                     if (TokenMatch(buffer,"mat",3))
                     {