After gaining __alloc_size hints, GCC thinks it can reach a memcpy()
with eir_len == 0 (since it can't see into the rewrite of status).
Instead, check eir_len == 0, avoiding this future warning:
In function 'eir_append_data',
inlined from 'read_local_oob_ext_data_complete' at net/bluetooth/mgmt.c:7210:12:
./include/linux/fortify-string.h:54:29: warning: '__builtin_memcpy' offset 5 is out of the bounds [0, 3] [-Warray-bounds]
...
net/bluetooth/hci_request.h:133:2: note: in expansion of macro 'memcpy'
133 | memcpy(&eir[eir_len], data, data_len);
| ^~~~~~
Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: linux-bluetooth@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>