Remove getsebool/setsebool from init and toolbox.

These were leftovers from the SELinux boolean support that
was originally merged.  Since Android prohibits SELinux policy
booleans, we can just drop it.

Change-Id: I02f646a7d8db65e153702205b082b87a73f60d73
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>