another petrification bit (trunk only)

Noticed while tracking down the "you die..." situation.  Duplicating
instapetrify()'s resistance checks is useful here, but there's no need to
also duplicate its death handling.

src/dokick.c

@@ -440,12 +440,10 @@ xchar x, y;
 	    if (poly_when_stoned(youmonst.data) && polymon(PM_STONE_GOLEM)) {
 		;	/* hero has been transformed but kick continues */
 	    } else {
-		You("turn to stone...");
-		killer.format = KILLED_BY;
 		/* normalize body shape here; foot, not body_part(FOOT) */
 		Sprintf(killer.name, "kicking %s barefoot",
 			killer_xname(kickobj));
-		done(STONING);
+		instapetrify(killer.name);
 	    }
 	}