selftests/bpf: Convert static to global in tc_redirect progs

Both IFINDEX_SRC and IFINDEX_DST are set from the userspace
and it won't work once bpf merges with bpf-next.

Fixes: 096eccde ("selftests/bpf: Rewrite test_tc_redirect.sh as prog_tests/tc_redirect.c")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210514170528.3750250-1-sdf@google.com

tools/testing/selftests/bpf/progs/test_tc_neigh.c

@@ -33,8 +33,8 @@
 				 a.s6_addr32[3] == b.s6_addr32[3])
 #endif
 
-static volatile const __u32 IFINDEX_SRC;
-static volatile const __u32 IFINDEX_DST;
+volatile const __u32 IFINDEX_SRC;
+volatile const __u32 IFINDEX_DST;
 
 static __always_inline bool is_remote_ep_v4(struct __sk_buff *skb,
 					    __be32 addr)

tools/testing/selftests/bpf/progs/test_tc_peer.c

@@ -8,8 +8,8 @@
 
 #include <bpf/bpf_helpers.h>
 
-static volatile const __u32 IFINDEX_SRC;
-static volatile const __u32 IFINDEX_DST;
+volatile const __u32 IFINDEX_SRC;
+volatile const __u32 IFINDEX_DST;
 
 SEC("classifier/chk_egress")
 int tc_chk(struct __sk_buff *skb)