iwlwifi: fix build error (iwl-rx.c).

This patch adds #ifdef CONFIG_IWLWIFI_DEBUG in iwl_rx_reply_rx()
method in iwlwifi/iwl-rx.c) to avoid build error  caused by "iwlwifi:
implement iwl_debug_report_frame for iwlagn".
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-rx.c

@@ -1071,9 +1071,10 @@ void iwl_rx_reply_rx(struct iwl_priv *priv,
 		priv->last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;
 
 	/* Set "1" to report good data frames in groups of 100 */
+#ifdef CONFIG_IWLWIFI_DEBUG
 	if (unlikely(priv->debug_level & IWL_DL_RX))
 		iwl_dbg_report_frame(priv, rx_start, len, header, 1);
-
+#endif
 	IWL_DEBUG_STATS_LIMIT("Rssi %d, noise %d, qual %d, TSF %llu\n",
 		rx_status.signal, rx_status.noise, rx_status.signal,
 		(unsigned long long)rx_status.mactime);