Revert "binfmt_elf: move brk out of mmap when doing direct loader exec"

This reverts commit c0ccb4da
("binfmt_elf: move brk out of mmap when doing direct loader exec")

See: https://github.com/raspberrypi/linux/issues/3271



Signed-off-by: Phil Elwell <phil@raspberrypi.org>