staging: Greybus: Remove unnecessary braces for single statement block

This patch fixes the following checkpath.pl warning
WARNING: braces {} are not necessary for single statement blocks

Signed-off-by: Rahul Krishnan <mrahul.krishnan@gmail.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>