[PATCH bpf-next] libbpf: fix perf_buffer__free() API for sparse allocs

[Eelco Chaudron <echaudro@xxxxxxxxxx>]

In case the cpu_bufs are sparsely allocated they are not
all free'ed. These changes will fix this.

Signed-off-by: Eelco Chaudron <echaudro@xxxxxxxxxx>
---
 tools/lib/bpf/libbpf.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5d60de6fd818..74d967619dcf 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8137,9 +8137,12 @@ void perf_buffer__free(struct perf_buffer *pb)
 	if (!pb)
 		return;
 	if (pb->cpu_bufs) {
-		for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) {
+		for (i = 0; i < pb->cpu_cnt; i++) {
 			struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
 
+			if (!cpu_buf)
+				continue;
+
 			bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
 			perf_buffer__free_cpu_buf(pb, cpu_buf);
 		}