Fix warning for Android NDK compiler: "function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]"

https://stackoverflow.com/questions/42125/warning-error-function-declaration-isnt-a-prototype
In C int foo() and int foo(void) are different functions. int foo() accepts an arbitrary number of arguments, while int foo(void) accepts 0 arguments. In C++ they mean the same thing.

test/testaudiostreamdynamicresample.c

@@ -102,7 +102,7 @@ static void draw_textf(SDL_Renderer* renderer, int x, int y, const char* fmt, ..
     draw_text(renderer, x, y, text);
 }
 
-static void queue_audio()
+static void queue_audio(void)
 {
     Uint8* new_data = NULL;
     int new_len = 0;

test/testautomation_log.c

@@ -21,7 +21,7 @@ static void EnableTestLog(int *message_count)
     SDL_SetLogOutputFunction(TestLogOutput, message_count);
 }
 
-static void DisableTestLog()
+static void DisableTestLog(void)
 {
     SDL_SetLogOutputFunction(original_function, original_userdata);
 }

test/testgles.c

@@ -50,7 +50,7 @@ quit(int rc)
 }
 
 static void
-Render()
+Render(void)
 {
     static GLubyte color[8][4] = { { 255, 0, 0, 0 },
                                    { 255, 0, 0, 255 },