man/io_uring_prep_msg_ring: add note on sending to a disabled ring
If the target ring isn't enabled yet, then we should also expect a
failure.
@@ -83,7 +83,8 @@ One of the fields set in the SQE was invalid.
.B -EBADFD
The descriptor passed in
.I fd
-does not refer to an io_uring file descriptor.
+does not refer to an io_uring file descriptor, or the ring is in a disabled
+state.
.TP
.B -EOVERFLOW
The kernel was unable to fill a CQE on the target ring. This can happen if
