tracing: Remove extra call to init_ftrace_syscalls()

trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().

Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.

Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org

Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -6918,7 +6918,6 @@ void __init trace_init(void)
 			tracepoint_printk = 0;
 	}
 	tracer_alloc_buffers();
-	init_ftrace_syscalls();
 	trace_event_init();	
 }