scsi: qla2xxx: Suppress two recently introduced compiler warnings

Suppress the following two compiler warnings because these are not useful:

In file included from ./include/trace/define_trace.h:102,
                 from ./include/trace/events/qla.h:39,
                 from drivers/scsi/qla2xxx/qla_dbg.c:77:
./include/trace/events/qla.h: In function 'trace_event_raw_event_qla_log_event':
./include/trace/trace_events.h:691:9: warning: function 'trace_event_raw_event_qla_log_event' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
  691 |  struct trace_event_raw_##call *entry;    \
      |         ^~~~~~~~~~~~~~~~
./include/trace/events/qla.h:12:1: note: in expansion of macro 'DECLARE_EVENT_CLASS'
   12 | DECLARE_EVENT_CLASS(qla_log_event,
      | ^~~~~~~~~~~~~~~~~~~
In file included from ./include/trace/define_trace.h:103,
                 from ./include/trace/events/qla.h:39,
                 from drivers/scsi/qla2xxx/qla_dbg.c:77:
./include/trace/events/qla.h: In function 'perf_trace_qla_log_event':
./include/trace/perf.h:41:9: warning: function 'perf_trace_qla_log_event' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
   41 |  struct hlist_head *head;     \
      |         ^~~~~~~~~~
./include/trace/events/qla.h:12:1: note: in expansion of macro 'DECLARE_EVENT_CLASS'

Link: https://lore.kernel.org/r/20200518211712.11395-3-bvanassche@acm.org
Fixes: 598a90f ("scsi: qla2xxx: add ring buffer for tracing debug logs")
Cc: Rajan Shanmugavelu <rajan.shanmugavelu@oracle.com>
Cc: Joe Jin <joe.jin@oracle.com>
Cc: Nilesh Javali <njavali@marvell.com>
Cc: Quinn Tran <qutran@marvell.com>
Cc: Martin Wilck <mwilck@suse.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/trace/events/qla.h

@@ -9,6 +9,11 @@
 
 #define QLA_MSG_MAX 256
 
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
+#endif
+
 DECLARE_EVENT_CLASS(qla_log_event,
 	TP_PROTO(const char *buf,
 		struct va_format *vaf),
@@ -27,6 +32,8 @@ DECLARE_EVENT_CLASS(qla_log_event,
 	TP_printk("%s %s", __get_str(buf), __get_str(msg))
 );
 
+#pragma GCC diagnostic pop
+
 DEFINE_EVENT(qla_log_event, ql_dbg_log,
 	TP_PROTO(const char *buf, struct va_format *vaf),
 	TP_ARGS(buf, vaf)