[compile] Suppress unused variables warning

Bug: 77973
Change-Id: Ifb5898234ee7e8cc66e2dac50cb2915e098b4e51
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/iperf/+/538887
Reviewed-by: Petr Hosek <phosek@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 561b5fb..20904f5 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -92,6 +92,8 @@
     "-Wno-int-conversion",
     "-Wno-pointer-sign",
     "-Wno-sign-compare",
+    "-Wno-unused-but-set-parameter",
+    "-Wno-unused-but-set-variable",
   ]
   if (is_fuchsia) {
     deps = [