Fix more -Wmaybe-uninitialized warnings that appear when
building the server with GCC 9 and PGO+LTO turned on.

Also avoid using lld when LTO is turned on as this lead
to unknown symbols during linking (lld was already turned
off for PGO).

Change-Id: I9151ec56707b8ad35ba941fefe1c8469e9bb1f4e