bus: fix build with CONFIG_UIDGID_STRICT_TYPE_CHECKS=y

bus.c: In function ‘kdbus_bus_uid_is_privileged’:
bus.c:37:21: error: invalid operands to binary == (have ‘kuid_t’ and ‘kuid_t’)

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
connection: fix build with CONFIG_UIDGID_STRICT_TYPE_CHECKS=y

connection.c: In function ‘kdbus_conn_ioctl_control’:
connection.c:1047:8: error: incompatible types when assigning to type ‘gid_t’ from type ‘kgid_t’
connection.c:1051:9: error: incompatible type for argument 5 of ‘kdbus_bus_new’

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>