p54: memset(0) whole array

gcc 7 complains:
drivers/net/wireless/intersil/p54/fwio.c: In function 'p54_scan':
drivers/net/wireless/intersil/p54/fwio.c:491:4: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]

Fix that by passing the correct size to memset.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/intersil/p54/fwio.c

@@ -488,7 +488,7 @@ int p54_scan(struct p54_common *priv, u16 mode, u16 dwell)
 
 			entry += sizeof(__le16);
 			chan->pa_points_per_curve = 8;
-			memset(chan->curve_data, 0, sizeof(*chan->curve_data));
+			memset(chan->curve_data, 0, sizeof(chan->curve_data));
 			memcpy(chan->curve_data, entry,
 			       sizeof(struct p54_pa_curve_data_sample) *
 			       min((u8)8, curve_data->points_per_channel));