VZ containers: Bug fixes
VZ containers: Bug fixes

1) added missed break in switch statement
2) changed bad error message in pre_setup env
3) prevent second chdir in vzctl_chroot
4) added file descriptors transmission to execve in vz_enter_execve

Signed-off-by: Alexander Burluka <e1a296dbcd92383e62ed2d193750f7aed5ae3091@parallels.com>

LK4D4/libct,LK4D4/libct,LK4D4/libct,hallyn/libct,avagin/libct,avagin/libct,xemul/libct,xemul/libct,avagin/libct,hallyn/libct,hallyn/libct,xemul/libct,xemul/libct