tracing: synth events: increase max fields count

Sometimes it is useful to construct larger synthetic trace events. Increase
'SYNTH_FIELDS_MAX' (maximum number of fields in a synthetic event) from 32 to
64.

Link: https://lkml.kernel.org/r/[e-mail]

Signed-off-by: Artem Bityutskiy <[e-mail]>
Acked-by: Tom Zanussi <[e-mail]>
Signed-off-by: Steven Rostedt (VMware) <[e-mail]>

kernel/trace/trace_synth.h

···
 #include "trace_dynevent.h"
 
 #define SYNTH_SYSTEM		"synthetic"
-#define SYNTH_FIELDS_MAX	32
+#define SYNTH_FIELDS_MAX	64
 
 #define STR_VAR_LEN_MAX		MAX_FILTER_STR_VAL /* must be multiple of sizeof(u64) */