Pass cl.viewentity into S_StartSound for pfnPlaySoundByNameAtLocation

This fixes a minor bug where sounds played via pfnPlaySoundByNameAtLocation (mainly from viewmodel animations e.g. MP5) would be left where it was emitted in the world, rather than following the local player as it does in Goldsrc.

engine/client/cl_game.c

@@ -2228,7 +2228,7 @@ static pmtrace_t *pfnTraceLine( float *start, float *end, int flags, int usehull
 static void GAME_EXPORT pfnPlaySoundByNameAtLocation( char *szSound, float volume, float *origin )
 {
 	int hSound = S_RegisterSound( szSound );
-	S_StartSound( origin, 0, CHAN_AUTO, hSound, volume, ATTN_NORM, PITCH_NORM, 0 );
+	S_StartSound( origin, cl.viewentity, CHAN_AUTO, hSound, volume, ATTN_NORM, PITCH_NORM, 0 );
 }
 
 /*