Init FF override ratio properly

libretro/libretro-core.c

@@ -390,6 +390,7 @@ void retro_fastforwarding(bool enabled)
    if (enabled && frontend_ff_enabled)
       return;
 
+   ff_override.ratio          = -1;
    ff_override.fastforward    = enabled;
    ff_override.inhibit_toggle = enabled;
    libretro_ff_enabled        = enabled;