bpf: fix return in load_bpf_file

The function load_bpf_file ignores the return value of
load_and_attach(), so even if load_and_attach() returns an error,
load_bpf_file() will return 0.

Now, load_bpf_file() can call load_and_attach() multiple times and some
can succeed and some could fail. I think the correct behavor is to
return error on the first failed load_and_attach().

v2: Added missing SOB

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

samples/bpf/bpf_load.c

@@ -567,8 +567,12 @@ static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
 		    memcmp(shname, "perf_event", 10) == 0 ||
 		    memcmp(shname, "socket", 6) == 0 ||
 		    memcmp(shname, "cgroup/", 7) == 0 ||
-		    memcmp(shname, "sockops", 7) == 0)
-			load_and_attach(shname, data->d_buf, data->d_size);
+		    memcmp(shname, "sockops", 7) == 0) {
+			ret = load_and_attach(shname, data->d_buf,
+					      data->d_size);
+			if (ret != 0)
+				goto done;
+		}
 	}
 
 	ret = 0;