lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr

Follow the kernel conventions, rename addr_in_gen_pool to
gen_pool_has_addr.

[sjhuang@iluvatar.ai: fix Documentation/ too]
Link: http://lkml.kernel.org/r/20181229015914.5573-1-sjhuang@iluvatar.ai
Link: http://lkml.kernel.org/r/20181228083950.20398-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docs: remove :c:func: from genalloc.rst

As of 5.3, the automarkup extension will do the right thing with function()
notation, so we don't need to clutter the text with :c:func: invocations.
So remove them.

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

genalloc: Fix a set of docs build warnings

Commit 795ee30648c7 ("lib/genalloc: introduce chunk owners") made a number
of changes to the genalloc API and implementation but did not update the
documentation to match, leading to these docs build warnings:

./lib/genalloc.c:1: warning: 'gen_pool_add_virt' not found
./lib/genalloc.c:1: warning: 'gen_pool_alloc' not found
./lib/genalloc.c:1: warning: 'gen_pool_free' not found
./lib/genalloc.c:1: warning: 'gen_pool_alloc_algo' not found

Fix these by updating the docs to match new function locations and names,
and by completing the update of one kerneldoc comment.

Fixes: 795ee30648c7 ("lib/genalloc: introduce chunk owners")
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

doc: Add documentation for the genalloc subsystem

Genalloc/genpool has kerneldoc comments, but nothing has ever been pulled
into the docs themselves. Here's a first attempt, repurposed from an
article I wrote at https://lwn.net/Articles/729653/.

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