smbfs keeps track of the user space server process in conn_pid.  This converts
that track to use a struct pid instead of pid_t.  This keeps us safe from pid
wrap around issues and prepares the way for the pid namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>