rfkill: fix the rfkill reason property query and parsing

The udev property is RFKILL_HW_BLOCK_REASON and it is returned as a
bitmap in hexadecimal.

Fixes: 9c4fbbe1b8 ('rfkill: query the hardware rfkill reason from udev')

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1128

src/core/nm-rfkill-manager.c

@@ -211,9 +211,10 @@ recheck_killswitches(NMRfkillManager *self)
                                          G_MININT,
                                          G_MAXINT,
                                          -1);
+
         sysfs_reason = _nm_utils_ascii_str_to_int64(
-            udev_device_get_property_value(device, "RFKILL_STATE_REASON"),
-            10,
+            udev_device_get_property_value(device, "RFKILL_HW_BLOCK_REASON"),
+            16,
             G_MININT,
             G_MAXINT,
             1); /* defaults to SIGNAL in case the kernel does not support this */