build-sys: Make libsystemd-shared link to libsystemd-daemon

build-sys: Make libsystemd-shared link to libsystemd-daemon

Commit f934051c4d17d167bd8e46dd3c70a745e26fd2eb broke the build
because it made libsystemd-shared call sd_listen_fds() which is
defined in libsystemd-daemon.

This is a bit of a contortion because libsystemd-shared.la is a
noinst_LTLIBRARY, but libtool should do the right thing here and emit
DT_NEEDED on libsystemd-daemon.so for things that consume
libsystemd-shared.la.