[*] basic in-house cpp linting (#4039)

- add `#pragma once` to remainder files
- "correcter" defines (ANDROID), see https://groups.google.com/g/android-ndk/c/cf9_f1SLXls
- extra miscelly fixups

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4039
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>

src/video_core/buffer_cache/buffer_cache.h

@@ -801,7 +801,7 @@ void BufferCache<P>::UpdateVertexBufferSlot(u32 index, const Binding& binding) {
 template <class P>
 void BufferCache<P>::BindHostVertexBuffers() {
 
-#ifdef ANDROID
+#ifdef __ANDROID__
     const bool use_optimized_vertex_buffers = Settings::values.use_optimized_vertex_buffers.GetValue();
 #else
     constexpr bool use_optimized_vertex_buffers = true;