[PATCH] bpftool: Fix build with OpenSSL versions older than 3.0

[Leo Yan <leo.yan@arm.com>]

ERR_get_error_all() exists only in OpenSSL 3.0 and later. Older versions
lack this API, causing build failure:

  sign.c: In function 'display_openssl_errors':
  sign.c:40:21: warning: implicit declaration of function 'ERR_get_error_all'; did you mean 'ERR_get_error_line'? [-Wimplicit-function-declaration]
     40 |         while ((e = ERR_get_error_all(&file, &line, NULL, &data, &flags))) {
        |                     ^~~~~~~~~~~~~~~~~
        |                     ERR_get_error_line
  LINK    /tmp/build/perf/util/bpf_skel/.tmp/bootstrap/bpftool
  /usr/lib/gcc/x86_64-alpine-linux-musl/11.2.1/../../../../x86_64-alpine-linux-musl/bin/ld: /tmp/build/perf/util/bpf_skel/.tmp/bootstrap/sign.o: in function `display_openssl_errors.constprop.0':
  sign.c:(.text+0x59): undefined reference to `ERR_get_error_all'
  collect2: error: ld returned 1 exit status

Use the deprecated ERR_get_error_line_data() for OpenSSL < 3.0, and keep
using ERR_get_error_all() when available.

Fixes: 40863f4d6ef2 ("bpftool: Add support for signing BPF programs")
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
 tools/bpf/bpftool/sign.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/bpf/bpftool/sign.c b/tools/bpf/bpftool/sign.c
index b34f74d210e9..c98edd6d1dde 100644
--- a/tools/bpf/bpftool/sign.c
+++ b/tools/bpf/bpftool/sign.c
@@ -37,7 +37,11 @@ static void display_openssl_errors(int l)
 	int flags;
 	int line;
 
+#if OPENSSL_VERSION_MAJOR >= 3
 	while ((e = ERR_get_error_all(&file, &line, NULL, &data, &flags))) {
+#else
+	while ((e = ERR_get_error_line_data(&file, &line, &data, &flags))) {
+#endif
 		ERR_error_string_n(e, buf, sizeof(buf));
 		if (data && (flags & ERR_TXT_STRING)) {
 			p_err("OpenSSL %s: %s:%d: %s", buf, file, line, data);
-- 
2.34.1