avoid goto

gcc -Wjump-misses-init warns this goto.  That is a false alert.
However why on earth do we need to use goto here?

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61944 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm_insnhelper.c

@@ -940,14 +940,6 @@ vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
 	    if (LIKELY(index < ROBJECT_NUMIV(obj))) {
 		val = ROBJECT_IVPTR(obj)[index];
 	    }
-	  undef_check:
-	    if (UNLIKELY(val == Qundef)) {
-		if (!is_attr && RTEST(ruby_verbose))
-		    rb_warning("instance variable %"PRIsVALUE" not initialized", QUOTE_ID(id));
-		val = Qnil;
-	    }
-	    RB_DEBUG_COUNTER_INC(ivar_get_ic_hit);
-	    return val;
 	}
 	else {
 	    st_data_t index;
@@ -967,8 +959,14 @@ vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
 		    }
 		}
 	    }
-	    goto undef_check;
 	}
+	if (UNLIKELY(val == Qundef)) {
+	    if (!is_attr && RTEST(ruby_verbose))
+		rb_warning("instance variable %"PRIsVALUE" not initialized", QUOTE_ID(id));
+	    val = Qnil;
+	}
+	RB_DEBUG_COUNTER_INC(ivar_get_ic_hit);
+	return val;
     }
     else {
 	RB_DEBUG_COUNTER_INC(ivar_get_ic_miss_noobject);