Fix compile failure on Solaris with Sun Studio

Change-Id: I37b677671565f83e2b67367a5080c9691831f845
Reviewed-on: http://review.couchbase.org/25226
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>