drbd: Request lookup code cleanup (2)

Unify the ar_id_to_req() and ack_id_to_req() functions: make both fail
if the consistency check fails.  Move the request lookup code now
duplicated in both functions into its own function.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
1 file changed