Make bpf_program__load consistent with other interfaces: use __u32
instead of u32. That in turn fixes build of samples:
In file included from ./samples/bpf/trace_output_user.c:21:0:
./tools/lib/bpf/libbpf.h:132:9: error: unknown type name ‘u32’
         u32 kern_version);
         ^
Fixes: commit 29cd77f41620d ("libbpf: Support loading individual progs")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
 
 int
 bpf_program__load(struct bpf_program *prog,
-                 char *license, u32 kern_version)
+                 char *license, __u32 kern_version)
 {
        int err = 0, fd, i;
 
 
 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
 
 int bpf_program__load(struct bpf_program *prog, char *license,
-                     u32 kern_version);
+                     __u32 kern_version);
 int bpf_program__fd(struct bpf_program *prog);
 int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
                              int instance);