eliminate static analysis complaints about eat.c

This is fairly ridiculous but it prevents the bogus complaints
when compiling eat.c with 'gcc -fanalyzer' about some fields in
gc.context.victual being used without having been initialized.

There's bound to be a better way to handle this and I'm curious
whether it will work with the 'onefile' testing.

src/eat.c

@@ -2983,6 +2983,9 @@ use_tin_opener(struct obj *obj)
 static int
 bite(void)
 {
+    /* hack to pacify static analyzer incorporated into gcc 12.2 */
+    sa_victual(&gc.context.victual);
+
     if (gc.context.victual.canchoke && u.uhunger >= 2000) {
         choke(gc.context.victual.piece);
         return 1;