net: lwip: fix dhcp_loop()

The local variables ipstr, maskstr and gwstr in static function
dhcp_loop() cannot be pointers to read-only data, since they may be
written to in case the device index is > 0. Therefore make them char
arrays allocated on the stack.

Reported-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
1 file changed