Fix false positive with dynamic literals in `Lint/LiteralsComparison`

spec/ameba/rule/lint/literals_comparison_spec.cr

@@ -6,6 +6,8 @@ module Ameba::Rule::Lint
   describe LiteralsComparison do
     it "passes for valid cases" do
       expect_no_issues subject, <<-CRYSTAL
+        {start.year, start.month} == {stop.year, stop.month}
+        ["foo"] === [foo]
         "foo" == foo
         "foo" != foo
         foo == "foo"
@@ -15,8 +17,8 @@ module Ameba::Rule::Lint
 
     it "reports if there is a dynamic comparison possibly evaluating to the same" do
       expect_issue subject, <<-CRYSTAL
-        [foo] === ["foo"]
-        # ^^^^^^^^^^^^^^^ error: Comparison most likely evaluates to the same
+        [foo] === [foo]
+        # ^^^^^^^^^^^^^ error: Comparison most likely evaluates to the same
         CRYSTAL
     end
 

src/ameba/rule/lint/literals_comparison.cr

@@ -36,14 +36,15 @@ module Ameba::Rule::Lint
       arg_is_literal, arg_is_static = literal_kind?(arg)
 
       return unless obj_is_literal && arg_is_literal
+      return unless obj.to_s == arg.to_s
 
       is_dynamic = !obj_is_static || !arg_is_static
 
       what =
         case node.name
         when "===" then "the same"
-        when "=="  then (obj.to_s == arg.to_s).to_s
-        when "!="  then (obj.to_s != arg.to_s).to_s
+        when "=="  then "true"
+        when "!="  then "false"
         end
 
       issue_for node, (is_dynamic ? MSG_LIKELY : MSG) % what