perf trace: Use macro RAW_SYSCALL_ARGS_NUM to replace number

This patch defines a macro RAW_SYSCALL_ARGS_NUM to replace the open
coded number '6'.

Signed-off-by: Leo Yan <[e-mail]>
Acked-by: Ian Rogers <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-trace.c

···
 # define F_LINUX_SPECIFIC_BASE	1024
 #endif
 
+#define RAW_SYSCALL_ARGS_NUM	6
+
 /*
  * strtoul: Go from a string to a value, i.e. for msr: MSR_FS_BASE to 0xc0000100
  */
···
 		const char *sys_enter,
 			   *sys_exit;
 	}	   bpf_prog_name;
-	struct syscall_arg_fmt arg[6];
+	struct syscall_arg_fmt arg[RAW_SYSCALL_ARGS_NUM];
 	u8	   nr_args;
 	bool	   errpid;
 	bool	   timeout;
···
  */
 struct bpf_map_syscall_entry {
 	bool	enabled;
-	u16	string_args_len[6];
+	u16	string_args_len[RAW_SYSCALL_ARGS_NUM];
 };
 
 /*
···
 {
 	int idx;
 
-	if (nr_args == 6 && sc->fmt && sc->fmt->nr_args != 0)
+	if (nr_args == RAW_SYSCALL_ARGS_NUM && sc->fmt && sc->fmt->nr_args != 0)
 		nr_args = sc->fmt->nr_args;
 
 	sc->arg_fmt = calloc(nr_args, sizeof(*sc->arg_fmt));
···
 		sc->tp_format = trace_event__tp_format("syscalls", tp_name);
 	}
 
-	if (syscall__alloc_arg_fmts(sc, IS_ERR(sc->tp_format) ? 6 : sc->tp_format->format.nr_fields))
+	if (syscall__alloc_arg_fmts(sc, IS_ERR(sc->tp_format) ?
+					RAW_SYSCALL_ARGS_NUM : sc->tp_format->format.nr_fields))
 		return -ENOMEM;
 
 	if (IS_ERR(sc->tp_format))