Fix falsely flipped fire feeding (#47092)

Rename the negated boolean variable `no_fire` to `have_fire` and
un-negate its usage.

Make `have_fire` default true, so `player_activity::do_turn` will check
for the presence of fire at least once.

src/activity_item_handling.cpp

@@ -2947,6 +2947,7 @@ int get_auto_consume_moves( player &p, const bool food )
     return 0;
 }
 
+// Try to add fuel to a fire. Return true if there is both fire and fuel; return false otherwise.
 bool try_fuel_fire( player_activity &act, player &p, const bool starting_fire )
 {
     const tripoint pos = p.pos();

src/player_activity.cpp

@@ -212,9 +212,9 @@ void player_activity::do_turn( player &p )
     }
     // first to ensure sync with actor
     synchronize_type_with_actor();
-    // Should happen before activity or it may fail du to 0 moves
-    if( *this && type->will_refuel_fires() && !no_fire ) {
-        no_fire = !try_fuel_fire( *this, p );
+    // Should happen before activity or it may fail due to 0 moves
+    if( *this && type->will_refuel_fires() && have_fire ) {
+        have_fire = try_fuel_fire( *this, p );
     }
     if( calendar::once_every( 30_minutes ) ) {
         no_food_nearby_for_auto_consume = false;

src/player_activity.h

@@ -72,8 +72,9 @@ class player_activity
          */
         bool auto_resume = false;
         /** Flag that will suppress the relatively expensive fire refueling search process.
-        */
-        bool no_fire = true;
+         *  Initially assume there is a fire unless the activity proves not to have one.
+         */
+        bool have_fire = true;
 
         player_activity();
         // This constructor does not work with activities using the new activity_actor system