acpi, nfit: fix bus vs dimm confusion in xlat_status

Given dimms and bus commands share the same command number space we need
to be careful that we are translating status in the correct context.
Otherwise we can, for example, fail an ND_CMD_GET_CONFIG_SIZE command
because max_xfer is zero. It fails because that condition erroneously
correlates with the 'cleared == 0' failure of ND_CMD_CLEAR_ERROR.

Cc: <stable@vger.kernel.org>
Fixes: aef25338 ("libnvdimm, nfit: centralize command status translation")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>