staging: greybus: loopback: Fix up some alignment checkpatch issues

Some function prototypes do not match the expected alignment formatting
so fix that up so that checkpatch is happy.

Cc: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Cc: Johan Hovold <johan@kernel.org>
Cc: greybus-dev@lists.linaro.org
Cc: devel@driverdev.osuosl.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Alex Elder <elder@kernel.org>
Link: https://lore.kernel.org/r/20190825055429.18547-7-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>