[iperf3] Remove deprecated flag ZX_WAIT_ASYNC_ONCE

The ZX_WAIT_ASYNC_ONCE flag will be removed as it's superfluous.
The definition is still in place until all known users from third party
repos are fixed or notified.

Change-Id: I1a00cbfe17a5835d1516d36474fc40fb367e5d9d
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/iperf/+/461915
Reviewed-by: Marty Faltesek <mfaltesek@google.com>

src/fuchsia/fuchsia-compat.c

diff --git a/src/fuchsia/fuchsia-compat.c b/src/fuchsia/fuchsia-compat.c
index 85f956d..0eb99ed 100644
--- a/src/fuchsia/fuchsia-compat.c
+++ b/src/fuchsia/fuchsia-compat.c
@@ -75,7 +75,7 @@
 			goto cleanup;
 		}
 		uint64_t key = fd;
-		st = zx_object_wait_async(h, port, key, sigs, ZX_WAIT_ASYNC_ONCE);
+		st = zx_object_wait_async(h, port, key, sigs, 0);
 		if (st != ZX_OK) {
 			fprintf(stderr, "Can't wait on object %d.\n", st);
 			errno = EINVAL;