Documentation: kernel-parameters: clarify "module." parameters

The command-line parameters "dyndbg" and "async_probe" are not
parameters for kernel/module.c but instead they are for the
module that is being loaded. Try to make that distinction in the
help text.

OTOH, "module.sig_enforce" is handled as a parameter of kernel/module.c
so "module." is correct for it.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/67d40b6d-c073-a3bf-cbb6-6cad941cceeb@infradead.org


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