Fix compile error with sun studio

"src/event.c", line 172: error: statement not reached (E_STATEMENT_NOT_REACHED)

Change-Id: Iee46423f254351042031d5656964fd439508608a
Reviewed-on: http://review.couchbase.org/25726
Tested-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>