Remove unneeded trailing semi-colons from Ruby files

lib/mruby/presym.rb

@@ -102,7 +102,7 @@ module MRuby
       @list_path ||= "#{@build.build_dir}/presym".freeze
     end
 
-    def header_dir;
+    def header_dir
       @header_dir ||= "#{@build.build_dir}/include/mruby/presym".freeze
     end
 

test/t/module.rb

@@ -686,7 +686,7 @@ end
   #    assert_nothing_raised(SystemStackError, bug10847) do
   #      0.3.numerator
   #    end
-  #  end;
+  #  end
   #end
 
   assert 'Module#prepend to frozen class' do

test/t/string.rb

@@ -507,8 +507,8 @@ assert('String#replace', '15.2.10.5.28') do
 
   b = 'abc' * 10
   c = ('cba' * 10).dup
-  b.replace(c);
-  c.replace(b);
+  b.replace(c)
+  c.replace(b)
   assert_equal c, b
 
   # shared string