log.h

We already do this for init, but had failed to do it for ueventd
and could not capture any logging from libselinux calls made by
ueventd.

Truly enabling non-error logging also requires uncommenting a line
in Android.mk:
LOCAL_CFLAGS += -DLOG_UEVENTS=1
which enables other logging and sets the default log level to INFO,
or otherwise changing the klog level in the ueventd code (is not
settable by init.rc loglevel).

Change-Id: I00e6f9d6271f2a21d9078c96368816d74d6d2850
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>