selftests/bpf: Undo GCC-specific bpf_helpers.h changes

Having GCC provide its own bpf-helper.h is not the right approach and is
going to be changed. Undo bpf_helpers.h change before moving
bpf_helpers.h into libbpf.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-2-andriin@fb.com

tools/testing/selftests/bpf/bpf_helpers.h

@@ -15,8 +15,6 @@
 			 ##__VA_ARGS__);		\
 })
 
-#ifdef __clang__
-
 /* helper macro to place programs, maps, license in
  * different sections in elf_bpf file. Section names
  * are interpreted by elf_bpf loader
@@ -47,12 +45,6 @@ struct bpf_map_def {
 	unsigned int numa_node;
 };
 
-#else
-
-#include <bpf-helpers.h>
-
-#endif
-
 #define BPF_ANNOTATE_KV_PAIR(name, type_key, type_val)		\
 	struct ____btf_map_##name {				\
 		type_key key;					\