man/udevadm: update device-id-of-file arguments

udevadm info rejects positional devices together with
--device-id-of-file=.

Document that behavior instead of saying positional arguments are
ignored.

Reproducer:
  udevadm info --device-id-of-file=/etc/passwd /sys

Before:
  Devices are not allowed with -d/--device-id-of-file and -c/--cleanup-db.

Follow-up:
  31767b92a0

man/udevadm.xml

@@ -240,7 +240,7 @@
           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
           <listitem>
             <para>Print major/minor numbers of the underlying device, where the file lives on.
-            If this is specified, all positional arguments are ignored.</para>
+            If this is specified, no positional arguments are accepted.</para>
           </listitem>
         </varlistentry>
         <varlistentry>