Fix V4L usage.

ff527de0 was submitted to 5.3 while cddbe873

 was submitted to 5.4.
The former's behavior was not preserved when 5.3 got merged into 5.4.

Change-Id: I7435ea30634001ae6e87c316eb8a8ab6f5e988e3
Reviewed-by: Lisandro Damián Nicanor Pérez Meyer <perezmeyer@gmail.com>
Reviewed-by: Andrew den Exter <andrew.den.exter@qinetic.com.au>