iwlwifi: fix debug message level

Debug messages should be printed using dev_dbg() not
dev_err() which requires DEBUG to be defined.
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

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

@@ -61,6 +61,9 @@
  *
  *****************************************************************************/
 
+#define DEBUG
+
+#include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/export.h>
 #include "iwl-debug.h"
@@ -124,7 +127,7 @@ void __iwl_dbg(struct device *dev,
 #ifdef CONFIG_IWLWIFI_DEBUG
 	if (iwl_have_debug_level(level) &&
 	    (!limit || net_ratelimit()))
-		dev_err(dev, "%c %s %pV", in_interrupt() ? 'I' : 'U',
+		dev_dbg(dev, "%c %s %pV", in_interrupt() ? 'I' : 'U',
 			function, &vaf);
 #endif
 	trace_iwlwifi_dbg(level, in_interrupt(), function, &vaf);