[RFC PATCH v4 09/12] nvdimm/pmem: Cleanup alloc_dax() error handling

[Mathieu Desnoyers]

Now that alloc_dax() returns ERR_PTR(-EOPNOTSUPP) rather than NULL,
the callers do not have to handle NULL return values anymore.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Alasdair Kergon <a...@redhat.com>
Cc: Mike Snitzer <snit...@kernel.org>
Cc: Mikulas Patocka <mpato...@redhat.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Vishal Verma <vishal.l.ve...@intel.com>
Cc: Dave Jiang <dave.ji...@intel.com>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Arnd Bergmann <a...@arndb.de>
Cc: Russell King <li...@armlinux.org.uk>
Cc: linux-a...@vger.kernel.org
Cc: linux-...@vger.kernel.org
Cc: linux-fsde...@vger.kernel.org
Cc: linux...@kvack.org
Cc: linux-...@vger.kernel.org
Cc: dm-devel@lists.linux.dev
Cc: nvd...@lists.linux.dev
---
 drivers/nvdimm/pmem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index f1d9f5c6dbac..e9898457a7bd 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -558,8 +558,8 @@ static int pmem_attach_disk(struct device *dev,
        disk->bb = &pmem->bb;
 
        dax_dev = alloc_dax(pmem, &pmem_dax_ops);
-       if (IS_ERR_OR_NULL(dax_dev)) {
-               rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP;
+       if (IS_ERR(dax_dev)) {
+               rc = PTR_ERR(dax_dev);
                if (rc != -EOPNOTSUPP)
                        goto out;
        } else {
-- 
2.39.2