Use RAII to always close display at exit.

The reason for doing this is that swiftshader debug libraries will
fail with an assertion error if you "leak" objects. This lets us
run with the debug libraries for more comprehensible errors.

get_image.cpp

@@ -327,6 +327,22 @@ int setUniforms(const GLuint& program, const std::string& fragment_shader) {
   return EXIT_SUCCESS;
 }
 
+class TerminateEGLAtExit{
+  EGLDisplay display;
+
+  public:
+    TerminateEGLAtExit(EGLDisplay);
+    ~TerminateEGLAtExit();
+};
+
+TerminateEGLAtExit::TerminateEGLAtExit(EGLDisplay display){
+  this->display = display;
+}
+
+TerminateEGLAtExit::~TerminateEGLAtExit(){
+  auto succeeded = eglTerminate(this->display);
+  assert(succeeded);
+}
 /*---------------------------------------------------------------------------*/
 
 int main(int argc, char* argv[]) {
@@ -349,6 +365,8 @@ int main(int argc, char* argv[]) {
     return EXIT_FAILURE;
   }
 
+  TerminateEGLAtExit cleanup_display = display;
+
   bool persist = false;
   bool animate = false;
   bool exit_compile = false;