uuidd: Fix pid file so it has the correct pid number

uuidd: Fix pid file so it has the correct pid number

The pid file was getting created before the fork(), so it had the
incorrect pid number.  No one noticed for a while, since "uuidd -k"
will kill the daemon and it has enough automatic convenience functions
that it's usually not necessary to refer to the pid file except as a
convenient place for uuidd to lock against multiple instances of the
daemon starting up.

Addresses-Sourceforge-Bug: #1893244

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>