optparse.rb: regexp at lhs

* lib/optparse.rb (OptionParser::Switch#compsys): regexp literal
  should be lhs of =~.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43891 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/optparse.rb

@@ -447,7 +447,7 @@ class OptionParser
 
       (sopts+lopts).each do |opt|
         # "(-x -c -r)-l[left justify]" \
-        if opt =~ /^--\[no-\](.+)$/
+        if /^--\[no-\](.+)$/ =~ opt
           o = $1
           yield("--#{o}", desc.join(""))
           yield("--no-#{o}", desc.join(""))