mac80211: move clearing result into ieee80211_parse_ch_switch_ie()

Clear the csa_ie in ieee80211_parse_ch_switch_ie() where the data
is filled in, rather than in each caller.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mesh.c

@@ -960,7 +960,6 @@ ieee80211_mesh_process_chnswitch(struct ieee80211_sub_if_data *sdata,
 	}
 
 	memset(&params, 0, sizeof(params));
-	memset(&csa_ie, 0, sizeof(csa_ie));
 	err = ieee80211_parse_ch_switch_ie(sdata, elems, sband->band,
 					   sta_flags, sdata->vif.addr,
 					   &csa_ie);