iwlwifi: don't perform "echo test" when cmd queue stuck

Perform "echo test" when cmd queue stuck detected, somethime it will cause
calltrace. I am not sure how to fix it yet, just remove the action now until
find a better way to handle it.
Reported-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -1755,16 +1755,6 @@ static inline int iwl_check_stuck_queue(struct iwl_priv *priv, int txq)
 {
 	if (iwl_trans_check_stuck_queue(trans(priv), txq)) {
 		int ret;
-		if (txq == priv->shrd->cmd_queue) {
-			/*
-			 * validate command queue still working
-			 * by sending "ECHO" command
-			 */
-			if (!iwl_cmd_echo_test(priv))
-				return 0;
-			else
-				IWL_DEBUG_HC(priv, "echo testing fail\n");
-		}
 		ret = iwl_force_reset(priv, IWL_FW_RESET, false);
 		return (ret == -EAGAIN) ? 0 : 1;
 	}