Rename polyfodder() to polyfood()

'Polyfodder' is already a term frequently used by players to describe
items which are useful to hang on to specifically to zap polymorph at
(for example, extra unicorn horns, which can be turned into magic
markers).  Using it as the name of a macro which tests whether a food
item will polymorph the creature consuming it is somewhat confusing, and
I think 'polyfood' is a lot clearer.

include/obj.h

@@ -306,7 +306,7 @@ struct obj {
 #define ofood(o) ((o)->otyp == CORPSE || (o)->otyp == EGG || (o)->otyp == TIN)
     /* note: sometimes eggs and tins have special corpsenm values that
        shouldn't be used as an index into mons[]                       */
-#define polyfodder(obj) \
+#define polyfood(obj) \
     (ofood(obj) && (obj)->corpsenm >= LOW_PM                            \
      && (pm_to_cham((obj)->corpsenm) != NON_PM                          \
                     || dmgtype(&mons[(obj)->corpsenm], AD_POLY)))

src/do.c

@@ -850,7 +850,7 @@ engulfer_digests_food(struct obj *obj)
 
         if (obj->otyp == CORPSE) {
             could_petrify = touch_petrifies(&mons[obj->corpsenm]);
-            could_poly = polyfodder(obj);
+            could_poly = polyfood(obj);
             could_grow = (obj->corpsenm == PM_WRAITH);
             could_heal = (obj->corpsenm == PM_NURSE);
         } else if (obj->otyp == GLOB_OF_GREEN_SLIME) {

src/eat.c

@@ -3865,7 +3865,7 @@ Popeye(int threat)
                           && (mndx == PM_LIZARD || acidic(&mons[mndx])));
     /* polymorph into a fiery monster */
     case SLIMED:
-        return (boolean) polyfodder(otin);
+        return (boolean) polyfood(otin);
     /* no tins can cure these (yet?) */
     case SICK:
     case VOMITING:

src/mon.c

@@ -1374,7 +1374,7 @@ m_consume_obj(struct monst *mtmp, struct obj *otmp)
                                               || corpsenm == PM_LARGE_MIMIC
                                               || corpsenm == PM_GIANT_MIMIC));
         slimer = (otmp->otyp == GLOB_OF_GREEN_SLIME);
-        poly = polyfodder(otmp);
+        poly = polyfood(otmp);
         grow = mlevelgain(otmp);
         heal = mhealup(otmp);
         eyes = (otmp->otyp == CARROT);