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>