Return sane state value when no input is present.

src/control/input.c

@@ -218,7 +218,7 @@ int libvlc_input_get_state( libvlc_input_t *p_input,
 
     p_input_thread = libvlc_get_input_thread ( p_input, p_e );
     if ( libvlc_exception_raised( p_e ) )
-        return 6; /* Return ERROR_S (see include/vlc_input.c) */
+        return 0;
 
     var_Get( p_input_thread, "state", &val );
     vlc_object_release( p_input_thread );