[PATCH] CPT: correct handling of lock fd error codes
Undump in CPT is performed in 2 stages (create env and init process; full
undump). These 2 stages are separated with help of pipe: when this pipe is
closed from vzctl we can proceed with second stage in CPT.
So, possible scenario is following:
1. We are waiting in CPT in pipe_read() when pipe will be closed.
2. someone is sending signal to our task which is waiting in pipe_read().
3. pipe_read() exits with -ERESTARTSYS, but we ignore this error and continue
with undump process, but vzctl do not perform all intermediate stages, so we
can't proceed with undump.