MINOR: fd: get rid of FD_WAIT_*

These flags were used to ease a transition which has been completed,
so they're not needed anymore. Get rid of them.
diff --git a/include/types/fd.h b/include/types/fd.h
index c6e47f2..c9b50c2 100644
--- a/include/types/fd.h
+++ b/include/types/fd.h
@@ -51,11 +51,6 @@
 #define FD_POLL_DATA    (FD_POLL_IN  | FD_POLL_OUT)
 #define FD_POLL_STICKY  (FD_POLL_ERR | FD_POLL_HUP)
 
-/* flags that an I/O callback may return */
-#define FD_WAIT_READ    0x01
-#define FD_WAIT_WRITE   0x02
-#define FD_WAIT_BOTH    (FD_WAIT_READ|FD_WAIT_WRITE)
-
 /* bit values for fdtab[fd]->flags. Most of them are used to hold a value
  * consecutive to a behaviour change.
  */
diff --git a/src/ev_sepoll.c b/src/ev_sepoll.c
index 506ab31..7c1cf4c 100644
--- a/src/ev_sepoll.c
+++ b/src/ev_sepoll.c
@@ -466,19 +466,8 @@
 		if ((eo & FD_EV_MASK_W) == FD_EV_SPEC_W)
 			fdtab[fd].ev |= FD_POLL_OUT;
 
-		if (fdtab[fd].iocb && fdtab[fd].owner && fdtab[fd].ev) {
-			int wait = fdtab[fd].iocb(fd);
-
-			/* FIXME: warning, this will not work if both old and new
-			 * callbacks are used at the same time ! This is only a
-			 * temporary measure during the migration.
-			 */
-			if (wait & FD_WAIT_READ)
-				fdtab[fd].spec.e ^= (FD_EV_WAIT_R ^ FD_EV_SPEC_R);
-
-			if (wait & FD_WAIT_WRITE)
-				fdtab[fd].spec.e ^= (FD_EV_WAIT_W ^ FD_EV_SPEC_W);
-		}
+		if (fdtab[fd].iocb && fdtab[fd].owner && fdtab[fd].ev)
+			fdtab[fd].iocb(fd);
 
 		/* one callback might already have closed the fd by itself */
 		if (!fdtab[fd].owner)