Revert "Define bsd source for linux to get prototype gethostname"
Revert "Define bsd source for linux to get prototype gethostname"

This reverts commit 00fb138fa565b2c850ad95892d8229eaca50b758.

hudon/bson-ruby,mongodb/bson-ruby,mongodb/bson-ruby,ukblewis/bson-ruby,estolfo/bson-ruby,estolfo/bson-ruby,hudon/bson-ruby,agis-/bson-ruby,agis-/bson-ruby,estolfo/bson-ruby,mongodb/bson-ruby,ukblewis/bson-ruby,johnsimon/bson-ruby,ukblewis/bson-ruby,agis-/bson-ruby,estolfo/bson-ruby,johnsimon/bson-ruby,hudon/bson-ruby,mongodb/bson-ruby,ukblewis/bson-ruby,johnsimon/bson-ruby