tests: tail-2/pid: use a 3-second timeout, not 1

tests: tail-2/pid: use a 3-second timeout, not 1

* tests/tail-2/pid: When using the timeout program to ensuring that
tail -s.1 --pid=$PID_T_MAX does not wait forever, use a timeout longer
than 1 second.  A 1-second timeout could be too short on a very busy
system, and result in a timeout, and hence false-positive failure.

2009-09-30  Jim Meyering  <meyering@redhat.com>