locking/refcount: move kernel-doc markups to the proper place

Changeset a435b9a1 ("locking/refcount: Provide __refcount API to obtain the old value")
added a set of functions starting with __ that have a new
parameter, adding a series of new warnings:

	$ ./scripts/kernel-doc -none include/linux/refcount.h
	include/linux/refcount.h:169: warning: Function parameter or member 'oldp' not described in '__refcount_add_not_zero'
	include/linux/refcount.h:208: warning: Function parameter or member 'oldp' not described in '__refcount_add'
	include/linux/refcount.h:239: warning: Function parameter or member 'oldp' not described in '__refcount_inc_not_zero'
	include/linux/refcount.h:261: warning: Function parameter or member 'oldp' not described in '__refcount_inc'
	include/linux/refcount.h:291: warning: Function parameter or member 'oldp' not described in '__refcount_sub_and_test'
	include/linux/refcount.h:327: warning: Function parameter or member 'oldp' not described in '__refcount_dec_and_test'
	include/linux/refcount.h:347: warning: Function parameter or member 'oldp' not described in '__refcount_dec'

The issue is that the kernel-doc markups are now misplaced,
as they should be added just before the functions.

So, move the kernel-doc markups to the proper places,
in order to drop the warnings.

It should be noticed that git show produces a crappy output,
for this patch without "--patience" flag.

Fixes: a435b9a1 ("locking/refcount: Provide __refcount API to obtain the old value")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/7985c31d1ace591bc5e1faa05c367f1295b78afd.1603791716.git.mchehab+huawei@kernel.org


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