drbd: address enum mismatch warnings

gcc -Wextra warns about mixing drbd_state_rv with drbd_ret_code
in a couple of places:

drivers/block/drbd/drbd_nl.c: In function 'drbd_adm_set_role':
drivers/block/drbd/drbd_nl.c:777:14: warning: comparison between 'enum drbd_state_rv' and 'enum drbd_ret_code' [-Wenum-compare]
  777 |  if (retcode != NO_ERROR)
      |              ^~
drivers/block/drbd/drbd_nl.c:784:12: warning: implicit conversion from 'enum drbd_ret_code' to 'enum drbd_state_rv' [-Wenum-conversion]
  784 |    retcode = ERR_MANDATORY_TAG;
      |            ^
drivers/block/drbd/drbd_nl.c: In function 'drbd_adm_attach':
drivers/block/drbd/drbd_nl.c:1965:10: warning: implicit conversion from 'enum drbd_state_rv' to 'enum drbd_ret_code' [-Wenum-conversion]
 1965 |  retcode = rv;  /* FIXME: Type mismatch. */
      |          ^
drivers/block/drbd/drbd_nl.c: In function 'drbd_adm_connect':
drivers/block/drbd/drbd_nl.c:2690:10: warning: implicit conversion from 'enum drbd_state_rv' to 'enum drbd_ret_code' [-Wenum-conversion]
 2690 |  retcode = conn_request_state(connection, NS(conn, C_UNCONNECTED), CS_VERBOSE);
      |          ^
drivers/block/drbd/drbd_nl.c: In function 'drbd_adm_disconnect':
drivers/block/drbd/drbd_nl.c:2803:11: warning: implicit conversion from 'enum drbd_state_rv' to 'enum drbd_ret_code' [-Wenum-conversion]
 2803 |   retcode = rv;  /* FIXME: Type mismatch. */
      |           ^

In each case, both are passed into drbd_adm_finish(), which just takes
a 32-bit integer and is happy with either, presumably intentionally.

Restructure the code to pass either type directly in there in most
cases, avoiding the warnings.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20220406190715.1938174-3-christoph.boehmwalder@linbit.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>