Try to revert the test failure with Ruby CI

https://rubyci.org/logs/rubyci.s3.amazonaws.com/debian9/ruby-master/log/20191111T093005Z.fail.html.gz

lib/rubygems/core_ext/kernel_gem.rb

@@ -61,13 +61,9 @@ module Kernel
 
     spec = dep.to_spec
 
-    if spec
-      if Gem::LOADED_SPECS_MUTEX.owned?
-        spec.activate
-      else
-        Gem::LOADED_SPECS_MUTEX.synchronize { spec.activate }
-      end
-    end
+    Gem::LOADED_SPECS_MUTEX.synchronize do
+      spec.activate
+    end if spec
   end
 
   private :gem