samples/bpf: replace meaningless counter with tracex4

Currently, compiling samples/bpf with LLVM warns about the unused but
set variable with tracex4_user.

    ./samples/bpf/tracex4_user.c:54:14:
    warning: variable 'i' set but not used [-Wunused-but-set-variable]
        int map_fd, i, j = 0;
                    ^
                    1 warning generated.

This commit resolve this compiler warning by replacing the meaningless
counter.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-3-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c
index 227b05a..dee8f0a 100644 (file)
--- a/samples/bpf/tracex4_user.c
+++ b/samples/bpf/tracex4_user.c
@@ -51,7 +51,7 @@ int main(int ac, char **argv)
        struct bpf_program *prog;
        struct bpf_object *obj;
        char filename[256];
-       int map_fd, i, j = 0;
+       int map_fd, j = 0;
 
        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
        obj = bpf_object__open_file(filename, NULL);
@@ -82,7 +82,7 @@ int main(int ac, char **argv)
                j++;
        }
 
-       for (i = 0; ; i++) {
+       while (1) {
                print_old_objects(map_fd);
                sleep(1);
        }