Fix some warnings from clang's static code analyzer

src/apply.c

@@ -2036,8 +2036,8 @@ boolean quietly;
             You("don't have enough room in here.");
         return FALSE;
     }
-    x = cc->x;
-    y = cc->y;
+    x = cc ? cc->x : u.ux;
+    y = cc ? cc->y : u.uy;
     if (!isok(x, y)) {
         if (!quietly)
             You("cannot put the figurine there.");