staging: vchiq_core: avoid indention in poll_services_of_group

By converting the first and the third if statement into continue early
the function poll_services_of_group() can avoid 2 indention levels.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1621105859-30215-8-git-send-email-stefan.wahren@i2se.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>