[media] DaVinci-VPFE-Capture: Delete unnecessary braces in vpfe_isr()

Do not use curly brackets at one source code place
where a single statement should be sufficient.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>