global_init: do not count threads before daemonize()

global_init: do not count threads before daemonize()

We were verifying that there was only 1 thread (the presumably main()) when
we call daemonize.  However, with the new logging code, we stop a thread
right before the check, and /proc apparently updates asynchronously such
that our attempt to count running threads gives us a bad answer.

Just remove this kludgey check; we'll have to catch this class of bugs
the hard way.

Signed-off-by: Sage Weil <sage.weil@dreamhost.com>
Reviewed-by: Greg Farnum <greg@inktank.com>