Fix the warning message for dynamic symbol literal in condition

parse.y

@@ -11758,7 +11758,7 @@ cond0(struct parser_params *p, NODE *node, enum cond_type type, const YYLTYPE *l
 	break;
 
       case NODE_DSYM:
-	SWITCH_BY_COND_TYPE(type, warning, "string ")
+	SWITCH_BY_COND_TYPE(type, warning, "symbol ")
 	break;
 
       case NODE_LIT:

test/ruby/test_syntax.rb

@@ -1073,7 +1073,7 @@ eom
     assert_warning(/literal in condition/) do
       eval('1 if :foo')
     end
-    assert_warning(/literal in condition/) do
+    assert_warning(/symbol literal in condition/) do
       eval('1 if :"#{"foo".upcase}"')
     end