acpi/nfit: fix cmd_rc for acpi_nfit_ctl to always return a value

cmd_rc is passed in by reference to the acpi_nfit_ctl() function and the
caller expects a value returned. However, when the package is pass through
via the ND_CMD_CALL command, cmd_rc is not touched. Make sure cmd_rc is
always set.

Fixes: aef25338 ("libnvdimm, nfit: centralize command status translation")
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit/core.c

@@ -408,6 +408,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	const guid_t *guid;
 	int rc, i;
 
+	*cmd_rc = -EINVAL;
 	func = cmd;
 	if (cmd == ND_CMD_CALL) {
 		call_pkg = buf;
@@ -518,6 +519,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		 * If we return an error (like elsewhere) then caller wouldn't
 		 * be able to rely upon data returned to make calculation.
 		 */
+		*cmd_rc = 0;
 		return 0;
 	}