tools/lib/libbpf.c: fix string format to allow build on arm32

On arm32, 'cd tools/testing/selftests/bpf && make' fails with:

libbpf.c:80:10: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘int64_t {aka long long int}’ [-Werror=format=]
   (func)("libbpf: " fmt, ##__VA_ARGS__); \
          ^
libbpf.c:83:30: note: in expansion of macro ‘__pr’
 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
                              ^~~~
libbpf.c:1072:3: note: in expansion of macro ‘pr_warning’
   pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",

To fix, typecast 'key_size' and amend format string.
Signed-off-by: Sirio Balmelli <sirio@b-ad.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/lib/bpf/libbpf.c

@@ -1042,8 +1042,8 @@ static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
 	}
 
 	if (def->key_size != key_size) {
-		pr_warning("map:%s key_type:%s has BTF type_size:%ld != key_size:%u\n",
-			   map->name, name, key_size, def->key_size);
+		pr_warning("map:%s key_type:%s has BTF type_size:%u != key_size:%u\n",
+			   map->name, name, (unsigned int)key_size, def->key_size);
 		return -EINVAL;
 	}
 
@@ -1069,8 +1069,8 @@ static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
 	}
 
 	if (def->value_size != value_size) {
-		pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",
-			   map->name, name, value_size, def->value_size);
+		pr_warning("map:%s value_type:%s has BTF type_size:%u != value_size:%u\n",
+			   map->name, name, (unsigned int)value_size, def->value_size);
 		return -EINVAL;
 	}