Mark functions conn_khelper(), nla_put_drbd_cfg_context(),
nla_put_status_info() and get_one_status() as static in drbd/drbd_nl.c
because they are not used outside this file.

This eliminates the following warnings in drbd/drbd_nl.c:
drivers/block/drbd/drbd_nl.c:365:5: warning: no previous prototype for ‘conn_khelper’ [-Wmissing-prototypes]
drivers/block/drbd/drbd_nl.c:2727:5: warning: no previous prototype for ‘nla_put_drbd_cfg_context’ [-Wmissing-prototypes]
drivers/block/drbd/drbd_nl.c:2753:5: warning: no previous prototype for ‘nla_put_status_info’ [-Wmissing-prototypes]
drivers/block/drbd/drbd_nl.c:2895:5: warning: no previous prototype for ‘get_one_status’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>