docs: filesystems: fuse.rst: supress a Sphinx warning

Get rid of this warning:

    Documentation/filesystems/fuse.rst:2: WARNING: Explicit markup ends without a blank line; unexpected unindent.

Fixes: 8ab13bca

 ("Documentation: filesystems: convert fuse to RST")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/cad541ec7d8d220d57bd5d097d60c62da64054ac.1583250595.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>