autofs: change catatonic setting to a bit flag

Change the superblock info.  catatonic setting to be part of a flags bit
field.

Link: http://lkml.kernel.org/r/154296973142.9889.17275721668508589639.stgit@pluto-themaw-net


Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>