fsdax-output-address-in-dax_iomap_pfn-and-rename-it-v21

fsdax-output-address-in-dax_iomap_pfn-and-rename-it-v21

initialize `rc', per Dan.

Link: https://lore.kernel.org/linux-fsdevel/Yp8FUZnO64Qvyx5G@kili/
Link: https://lkml.kernel.org/r/20220607143837.161174-1-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>