[PATCH] bpf: selftests: Fix warning in flow_dissector

[Arthur Fabre]

Building the userspace part of the flow_dissector resulted in:

prog_tests/flow_dissector.c: In function ‘tx_tap’:
prog_tests/flow_dissector.c:176:9: warning: implicit declaration
of function ‘writev’; did you mean ‘write’? [-Wimplicit-function-declaration]
  return writev(fd, iov, ARRAY_SIZE(iov));
         ^~~~~~
         write

Include <sys/uio.h> to fix this.

Signed-off-by: Arthur Fabre <afa...@cloudflare.com>
---
 tools/testing/selftests/bpf/prog_tests/flow_dissector.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c 
b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index fbd1d88a6095..c938283ac232 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -3,6 +3,7 @@
 #include <error.h>
 #include <linux/if.h>
 #include <linux/if_tun.h>
+#include <sys/uio.h>
 
 #define CHECK_FLOW_KEYS(desc, got, expected)                           \
        CHECK_ATTR(memcmp(&got, &expected, sizeof(got)) != 0,           \
-- 
2.20.1