drbd: fix print_st_err()'s prototype to match the definition

print_st_err() is defined with its 4th argument taking an
'enum drbd_state_rv' but its prototype use an int for it.

Fix this by using 'enum drbd_state_rv' in the prototype too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_state.h

@@ -131,7 +131,7 @@ extern enum drbd_state_rv _drbd_set_state(struct drbd_device *, union drbd_state
 					  enum chg_state_flags,
 					  struct completion *done);
 extern void print_st_err(struct drbd_device *, union drbd_state,
-			union drbd_state, int);
+			union drbd_state, enum drbd_state_rv);
 
 enum drbd_state_rv
 _conn_request_state(struct drbd_connection *connection, union drbd_state mask, union drbd_state val,