nl80211: explicitly check enum nl80211_mesh_power_mode

Different gcc versions appear to be treating enum with different
signedness, causing warnings with the out parameter one way or
the other.

Just use the correct type to avoid all that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -5353,6 +5353,18 @@ static int nl80211_check_s32(const struct nlattr *nla, s32 min, s32 max, s32 *ou
 	return 0;
 }
 
+static int nl80211_check_power_mode(const struct nlattr *nla,
+				    enum nl80211_mesh_power_mode min,
+				    enum nl80211_mesh_power_mode max,
+				    enum nl80211_mesh_power_mode *out)
+{
+	u32 val = nla_get_u32(nla);
+	if (val < min || val > max)
+		return -EINVAL;
+	*out = val;
+	return 0;
+}
+
 static int nl80211_parse_mesh_config(struct genl_info *info,
 				     struct mesh_config *cfg,
 				     u32 *mask_out)
@@ -5497,7 +5509,7 @@ do {									    \
 				  NL80211_MESH_POWER_ACTIVE,
 				  NL80211_MESH_POWER_MAX,
 				  mask, NL80211_MESHCONF_POWER_MODE,
-				  nl80211_check_u32);
+				  nl80211_check_power_mode);
 	FILL_IN_MESH_PARAM_IF_SET(tb, cfg, dot11MeshAwakeWindowDuration,
 				  0, 65535, mask,
 				  NL80211_MESHCONF_AWAKE_WINDOW, nl80211_check_u16);