IB/hfi1: Suppress useless compiler warnings

These warnings can cause build failure:

In file included from ./include/trace/define_trace.h:102,
                 from drivers/infiniband/hw/hfi1/trace_dbg.h:111,
                 from drivers/infiniband/hw/hfi1/trace.h:15,
                 from drivers/infiniband/hw/hfi1/trace.c:6:
drivers/infiniband/hw/hfi1/./trace_dbg.h: In function ‘trace_event_get_offsets_hfi1_trace_template’:
./include/trace/trace_events.h:261:9: warning: function ‘trace_event_get_offsets_hfi1_trace_template’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
  struct trace_event_raw_##call __maybe_unused *entry;  \
         ^~~~~~~~~~~~~~~~
drivers/infiniband/hw/hfi1/./trace_dbg.h:25:1: note: in expansion of macro ‘DECLARE_EVENT_CLASS’
 DECLARE_EVENT_CLASS(hfi1_trace_template,
 ^~~~~~~~~~~~~~~~~~~
In file included from ./include/trace/define_trace.h:102,
                 from drivers/infiniband/hw/hfi1/trace_dbg.h:111,
                 from drivers/infiniband/hw/hfi1/trace.h:15,
                 from drivers/infiniband/hw/hfi1/trace.c:6:
drivers/infiniband/hw/hfi1/./trace_dbg.h: In function ‘trace_event_raw_event_hfi1_trace_template’:
./include/trace/trace_events.h:386:9: warning: function ‘trace_event_raw_event_hfi1_trace_template’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
  struct trace_event_raw_##call *entry;    \
         ^~~~~~~~~~~~~~~~
drivers/infiniband/hw/hfi1/./trace_dbg.h:25:1: note: in expansion of macro ‘DECLARE_EVENT_CLASS’
 DECLARE_EVENT_CLASS(hfi1_trace_template,
 ^~~~~~~~~~~~~~~~~~~
In file included from ./include/trace/define_trace.h:103,
                 from drivers/infiniband/hw/hfi1/trace_dbg.h:111,
                 from drivers/infiniband/hw/hfi1/trace.h:15,
                 from drivers/infiniband/hw/hfi1/trace.c:6:
drivers/infiniband/hw/hfi1/./trace_dbg.h: In function ‘perf_trace_hfi1_trace_template’:
./include/trace/perf.h:70:9: warning: function ‘perf_trace_hfi1_trace_template’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
  struct hlist_head *head;     \
         ^~~~~~~~~~
drivers/infiniband/hw/hfi1/./trace_dbg.h:25:1: note: in expansion of macro ‘DECLARE_EVENT_CLASS’
 DECLARE_EVENT_CLASS(hfi1_trace_template,
 ^~~~~~~~~~~~~~~~~~~

Solution adapted here is similar to the one in fbbc95a

Signed-off-by: Ehab Ababneh <ehab.ababneh@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/168088635415.3027109.5711716700328939402.stgit@252.162.96.66.static.eigbox.net
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hfi1/trace_dbg.h

@@ -22,6 +22,11 @@
 
 #define MAX_MSG_LEN 512
 
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
+#endif
+
 DECLARE_EVENT_CLASS(hfi1_trace_template,
 		    TP_PROTO(const char *function, struct va_format *vaf),
 		    TP_ARGS(function, vaf),
@@ -36,6 +41,8 @@ DECLARE_EVENT_CLASS(hfi1_trace_template,
 			      __get_str(msg))
 );
 
+#pragma GCC diagnostic pop
+
 /*
  * It may be nice to macroize the __hfi1_trace but the va_* stuff requires an
  * actual function to work and can not be in a macro.