[3.x] Prevent writing incorrect shader hints

(cherry picked from commit 25e24f2d05533645b58c6dce64e6533750a693c4)

servers/visual/shader_language.cpp

@@ -5996,6 +5996,7 @@ Error ShaderLanguage::_parse_shader(const Map<StringName, FunctionInfo> &p_funct
 
 						} else {
 							_set_error("Expected valid type hint after ':'.");
+							return ERR_PARSE_ERROR;
 						}
 
 						if (uniform2.hint != ShaderNode::Uniform::HINT_RANGE && uniform2.hint != ShaderNode::Uniform::HINT_NONE && uniform2.hint != ShaderNode::Uniform::HINT_COLOR && type <= TYPE_MAT4) {