wifi: mwifiex: remove unused evt_buf variable

clang with W=1 reports
drivers/net/wireless/marvell/mwifiex/11h.c:198:6: error: variable
  'evt_buf' set but not used [-Werror,-Wunused-but-set-variable]
        u8 *evt_buf;
            ^
This variable is not used so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230329131444.1809018-1-trix@redhat.com

drivers/net/wireless/marvell/mwifiex/11h.c

@@ -195,7 +195,6 @@ int mwifiex_11h_handle_chanrpt_ready(struct mwifiex_private *priv,
 {
 	struct host_cmd_ds_chan_rpt_event *rpt_event;
 	struct mwifiex_ie_types_chan_rpt_data *rpt;
-	u8 *evt_buf;
 	u16 event_len, tlv_len;
 
 	rpt_event = (void *)(skb->data + sizeof(u32));
@@ -208,8 +207,6 @@ int mwifiex_11h_handle_chanrpt_ready(struct mwifiex_private *priv,
 		return -1;
 	}
 
-	evt_buf = (void *)&rpt_event->tlvbuf;
-
 	while (event_len >= sizeof(struct mwifiex_ie_types_header)) {
 		rpt = (void *)&rpt_event->tlvbuf;
 		tlv_len = le16_to_cpu(rpt->header.len);
@@ -231,7 +228,6 @@ int mwifiex_11h_handle_chanrpt_ready(struct mwifiex_private *priv,
 			break;
 		}
 
-		evt_buf += (tlv_len + sizeof(rpt->header));
 		event_len -= (tlv_len + sizeof(rpt->header));
 	}