Pull libnvdimm fixes from Dave Jiang:
- ensure that a variable passed in by reference to acpi_nfit_ctl is
always set to a value. An incremental patch is provided due to notice
from testing in -next. The rest of the commits did not exhibit
issues.
- fix a return path in nsio_rw_bytes() that was not returning "bytes
remain" as expected for the function.
- address an issue where applications polling on scrub-completion for
the NVDIMM may falsely wakeup and read the wrong state value and
cause hang.
- change the test unit persistent capability attribute to fix up a
broken assumption in the unit test infrastructure wrt the
'write_cache' attribute
- ratelimit dev_info() in the dax device check_vma() function since
this is easily triggered from userspace
* tag 'libnvdimm-fixes-4.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
nfit: fix unchecked dereference in acpi_nfit_ctl
acpi, nfit: Fix scrub idle detection
tools/testing/nvdimm: advertise a write cache for nfit_test
acpi/nfit: fix cmd_rc for acpi_nfit_ctl to always return a value
dev-dax: check_vma: ratelimit dev_info-s
libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()