docs: lockdep-design: fix some warning issues

There are several warnings caused by a recent change
224ec489 ("lockdep/Documention: Recursive read lock detection reasoning")

Those are reported by htmldocs build:

    Documentation/locking/lockdep-design.rst:429: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/locking/lockdep-design.rst:452: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/locking/lockdep-design.rst:453: WARNING: Unexpected indentation.
    Documentation/locking/lockdep-design.rst:453: WARNING: Blank line required after table.
    Documentation/locking/lockdep-design.rst:454: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/locking/lockdep-design.rst:455: WARNING: Unexpected indentation.
    Documentation/locking/lockdep-design.rst:455: WARNING: Blank line required after table.
    Documentation/locking/lockdep-design.rst:456: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/locking/lockdep-design.rst:457: WARNING: Unexpected indentation.
    Documentation/locking/lockdep-design.rst:457: WARNING: Blank line required after table.

Besides the reported issues, there are some missing blank
lines that ended producing wrong html output, and some
literals are not properly identified.

Also, the symbols used at the irq enabled/disable table
are not displayed as expected, as they're not literals.
Also, on another table they're using a different notation.

Fixes: 224ec489 ("lockdep/Documention: Recursive read lock detection reasoning")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/3b9431ac5c01e38111cd59928a93e7259ab7db0f.1603791716.git.mchehab+huawei@kernel.org


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