namespace: remove stack allocations
namespace: remove stack allocations

Switch to a static stack instead of allocating a new one. There's really
no point in doing all of the dance to get the current pagesize.

Signed-off-by: Christian Brauner <48455ab3070520a2d174545c7239d6d0fabd9a83@ubuntu.com>

ss1h2a3tw/lxc,hallyn/lxc,hallyn/lxc,ss1h2a3tw/lxc,ss1h2a3tw/lxc,hallyn/lxc