Do not report type declarations within generic records

spec/ameba/rule/lint/useless_assign_spec.cr

@@ -394,6 +394,12 @@ module Ameba::Rule::Lint
           CRYSTAL
       end
 
+      it "doesn't report if this is a record declaration (generics)" do
+        expect_no_issues subject, <<-CRYSTAL
+          record Foo(T), foo : T
+          CRYSTAL
+      end
+
       it "doesn't report if this is an accessor declaration" do
         accessor_macros = %w[setter class_setter]
         %w[getter class_getter property class_property].each do |name|

src/ameba/ast/visitors/scope_visitor.cr

@@ -173,9 +173,10 @@ module Ameba::AST
       scope = @current_scope
 
       case
-      when scope.top_level? && record_macro?(node)         then return false
-      when scope.type_definition? && record_macro?(node)   then return false
-      when scope.type_definition? && accessor_macro?(node) then return false
+      when (scope.top_level? || scope.type_definition?) && record_macro?(node)
+        return false
+      when scope.type_definition? && accessor_macro?(node)
+        return false
       when scope.def? && special_node?(node)
         scope.arguments.each do |arg|
           ref = arg.variable.reference(scope)
@@ -194,7 +195,14 @@ module Ameba::AST
     end
 
     private def record_macro?(node)
-      node.name == "record" && node.args.first?.is_a?(Crystal::Path)
+      return false unless node.name == "record"
+
+      case node.args.first?
+      when Crystal::Path, Crystal::Generic
+        true
+      else
+        false
+      end
     end
 
     private def skip?(node)