If we want one CRIU binary to work across all AArch64 kernel
configurations, a single task size value cannot be hard coded.
This fixes the following error on AArch64 kernels with
CONFIG_ARM64_64K_PAGES=y.

  pie: Error (pie/restorer.c:772): Unable to unmap (-): -1211695104
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>