hostapd: fix a compiler warning in ap+station patch

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45062 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/network/services/hostapd/patches/370-ap_sta_support.patch

@@ -53,7 +53,7 @@
 +{
 +	const char *cmd = "STOP_AP";
 +	char buf[256];
-+	int len = sizeof(buf);
++	size_t len = sizeof(buf);
 +
 +	if (wpa_ctrl_request(wpa_s->hostapd, cmd, os_strlen(cmd), buf, &len, NULL) < 0) {
 +		wpa_printf(MSG_ERROR, "\nFailed to stop hostapd AP interfaces\n");
@@ -66,7 +66,7 @@
 +{
 +	char *cmd = NULL;
 +	char buf[256];
-+	int len = sizeof(buf);
++	size_t len = sizeof(buf);
 +	enum hostapd_hw_mode hw_mode;
 +	u8 channel;
 +	int sec_chan = 0;