Remove lcb_ prefix from static functions

Change-Id: I2440d4aa7adf1d9a903fe4dd58840c8ff7f6e338
Reviewed-on: http://review.couchbase.org/29744
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>