[rubygems/rubygems] Move traling `if` to the same line for readablity

https://github.com/rubygems/rubygems/commit/d722b8b578

lib/rubygems/installer.rb

@@ -704,8 +704,7 @@ class Gem::Installer
     return if self.class.path_warning
 
     user_bin_dir = @bin_dir || Gem.bindir(gem_home)
-    user_bin_dir = user_bin_dir.tr(File::ALT_SEPARATOR, File::SEPARATOR) if
-      File::ALT_SEPARATOR
+    user_bin_dir = user_bin_dir.tr(File::ALT_SEPARATOR, File::SEPARATOR) if File::ALT_SEPARATOR
 
     path = ENV['PATH']
     if Gem.win_platform?