[bpf-next v3 2/3] samples/bpf: replace meaningless counter with tracex4

["Daniel T. Lee" <danieltimlee@gmail.com>]

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>
---
 samples/bpf/tracex4_user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c
index 227b05a0bc88..dee8f0a091ba 100644
--- 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);
 	}
-- 
2.34.1