Fix condition

Leftovers from before tests were added.

Author: martincostello

src/OpenApi/src/Services/OpenApiGenerator.cs

@@ -451,7 +451,7 @@ private List<IOpenApiParameter> GetOpenApiParameters(MethodInfo methodInfo, Rout
         else if (parameter.ParameterType == typeof(IFormFile) ||
                  parameter.ParameterType == typeof(IFormFileCollection) ||
                  parameter.ParameterType == typeof(JsonPatchDocument) ||
-                 parameter.ParameterType == typeof(JsonPatchDocument<>))
+                 (parameter.ParameterType.IsGenericType && parameter.ParameterType.GetGenericTypeDefinition() == typeof(JsonPatchDocument<>)))
         {
             return (true, null, null);
         }