Staging: bcm: Qos.c: Replaced do-while(0) breaks with continue

This patch replaces the do-while(0); loop which is used for breaking if
a check fails by using the `continue` statement. This saves one
indentation level.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>