libbpf: Fix lookup_and_delete_elem_flags error reporting

Fix bpf_map_lookup_and_delete_elem_flags() to pass the return code through
libbpf_err_errno() as we do similarly in bpf_map_lookup_and_delete_elem().

Fixes: f12b654 ("libbpf: Streamline error reporting for low-level APIs")
Signed-off-by: Mehrdad Arshad Rad <arshad.rad@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211104171354.11072-1-arshad.rad@gmail.com

tools/lib/bpf/bpf.c

@@ -515,14 +515,16 @@ int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
 int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags)
 {
 	union bpf_attr attr;
+	int ret;
 
 	memset(&attr, 0, sizeof(attr));
 	attr.map_fd = fd;
 	attr.key = ptr_to_u64(key);
 	attr.value = ptr_to_u64(value);
 	attr.flags = flags;
 
-	return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
+	ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
+	return libbpf_err_errno(ret);
 }
 
 int bpf_map_delete_elem(int fd, const void *key)