fix libm linking
fix libm linking

http://trac.enlightenment.org/e/ticket/2339

FlorentRevest/Elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,rvandegrift/elementary,rvandegrift/elementary