dynamic debug is "expecting pairs of match-spec <value>" so the example
for all files of which the paths include "usb" there is "file" missing.
Signed-off-by: NMartin Kepplinger <martin.kepplinger@puri.sm>
Link: https://lore.kernel.org/r/20210303091646.773111-1-martin.kepplinger@puri.smSigned-off-by: NJonathan Corbet <corbet@lwn.net>