[rubygems/rubygems] Remove unnecessary condition

This variable can't be falsy.

https://github.com/rubygems/rubygems/commit/b838f9a6f0

lib/rubygems/ext/cargo_builder.rb

@@ -263,19 +263,17 @@ class Gem::Ext::CargoBuilder < Gem::Ext::Builder
       # Details: https://github.com/rubygems/rubygems/issues/977#issuecomment-171544940
       tmp_dest_relative = get_relative_path(tmp_dest.clone, extension_dir)
 
-      if tmp_dest_relative
-        full_tmp_dest = File.join(extension_dir, tmp_dest_relative)
+      full_tmp_dest = File.join(extension_dir, tmp_dest_relative)
 
-        # TODO: remove in RubyGems 3
-        if Gem.install_extension_in_lib && lib_dir
-          FileUtils.mkdir_p lib_dir
-          FileUtils.cp_r ext_path, lib_dir, remove_destination: true
-        end
+      # TODO: remove in RubyGems 3
+      if Gem.install_extension_in_lib && lib_dir
+        FileUtils.mkdir_p lib_dir
+        FileUtils.cp_r ext_path, lib_dir, remove_destination: true
+      end
 
-        FileUtils::Entry_.new(full_tmp_dest).traverse do |ent|
-          destent = ent.class.new(dest_path, ent.rel)
-          destent.exist? || FileUtils.mv(ent.path, destent.path)
-        end
+      FileUtils::Entry_.new(full_tmp_dest).traverse do |ent|
+        destent = ent.class.new(dest_path, ent.rel)
+        destent.exist? || FileUtils.mv(ent.path, destent.path)
       end
     ensure
       FileUtils.rm_rf tmp_dest if tmp_dest

lib/rubygems/ext/ext_conf_builder.rb

@@ -61,21 +61,19 @@ class Gem::Ext::ExtConfBuilder < Gem::Ext::Builder
 
         make dest_path, results, extension_dir
 
-        if tmp_dest_relative
-          full_tmp_dest = File.join(extension_dir, tmp_dest_relative)
+        full_tmp_dest = File.join(extension_dir, tmp_dest_relative)
 
-          # TODO remove in RubyGems 3
-          if Gem.install_extension_in_lib and lib_dir
-            FileUtils.mkdir_p lib_dir
-            entries = Dir.entries(full_tmp_dest) - %w[. ..]
-            entries = entries.map {|entry| File.join full_tmp_dest, entry }
-            FileUtils.cp_r entries, lib_dir, :remove_destination => true
-          end
+        # TODO remove in RubyGems 3
+        if Gem.install_extension_in_lib and lib_dir
+          FileUtils.mkdir_p lib_dir
+          entries = Dir.entries(full_tmp_dest) - %w[. ..]
+          entries = entries.map {|entry| File.join full_tmp_dest, entry }
+          FileUtils.cp_r entries, lib_dir, :remove_destination => true
+        end
 
-          FileUtils::Entry_.new(full_tmp_dest).traverse do |ent|
-            destent = ent.class.new(dest_path, ent.rel)
-            destent.exist? or FileUtils.mv(ent.path, destent.path)
-          end
+        FileUtils::Entry_.new(full_tmp_dest).traverse do |ent|
+          destent = ent.class.new(dest_path, ent.rel)
+          destent.exist? or FileUtils.mv(ent.path, destent.path)
         end
       ensure
         ENV["DESTDIR"] = destdir