Remove dummy input locking

Contrary to commit 719f12a6 log, input_GetItem() does not check for a
lock on the input. There may be need for locking here(?), but taking the
object lock would definitely not help, as this was the only place is the
entire tree using the generic object lock on an input object.

modules/misc/lua/libs/input.c

@@ -57,7 +57,6 @@ input_thread_t * vlclua_get_input_internal( lua_State *L )
 static int vlclua_input_info( lua_State *L )
 {
     input_thread_t * p_input = vlclua_get_input_internal( L );
-    vlc_object_lock( p_input );
     int i_cat;
     int i;
     if( !p_input ) return vlclua_error( L );
@@ -80,7 +79,6 @@ static int vlclua_input_info( lua_State *L )
         }
         lua_settable( L, -3 );
     }
-    vlc_object_unlock( p_input );
     vlc_object_release( p_input );
     return 1;
 }