libbpf: move logging helpers into libbpf_internal.h

libbpf_util.h header was recently exposed as public as a dependency of
xsk.h. In addition to memory barriers, it contained logging helpers,
which are not supposed to be exposed. This patch moves those into
libbpf_internal.h, which is kept as an internal header.

Cc: Stanislav Fomichev <sdf@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 7080da8909 ("libbpf: add libbpf_util.h to header install.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/libbpf_internal.h

@@ -21,6 +21,19 @@
 #define BTF_PARAM_ENC(name, type) (name), (type)
 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
 
+extern void libbpf_print(enum libbpf_print_level level,
+			 const char *format, ...)
+	__attribute__((format(printf, 2, 3)));
+
+#define __pr(level, fmt, ...)	\
+do {				\
+	libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__);	\
+} while (0)
+
+#define pr_warning(fmt, ...)	__pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...)	__pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...)	__pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
+
 int libbpf__probe_raw_btf(const char *raw_types, size_t types_len,
 			  const char *str_sec, size_t str_len);