supress warning from the module method call at first time.
supress warning from the module method call at first time.

avoid to print message below:
lib/celluloid/io/common_methods.rb:43: warning: instance variable @write_owner not initialized

ioquatix/celluloid-io,marshall-lee/celluloid-io,kenichi/celluloid-io,dilumn/celluloid-io,celluloid/celluloid-io