nfsdcld: make it watch for inotify events in the containing directory

nfsdcld: make it watch for inotify events in the containing directory

Before opening the pipe, set an inotify watch on the containing dir and
then try to open the pipe. If it succeeds, then set up pipe and inotify
events and return success. If it fails with -ENOENT, then just set up
the inotify event and return success. If it fails with any other error
then return the error and the caller can then abort the program.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>