tracing: Fix function timing profiler to initialize hashtable

Since the new fgraph requires to initialize fgraph_ops.ops.func_hash before
calling register_ftrace_graph(), initialize it with default (tracing all
functions) parameter.

Cc: stable@vger.kernel.org
Fixes: 5fccc75 ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -883,6 +883,10 @@ static void profile_graph_return(struct ftrace_graph_ret *trace,
 }
 
 static struct fgraph_ops fprofiler_ops = {
+	.ops = {
+		.flags = FTRACE_OPS_FL_INITIALIZED,
+		INIT_OPS_HASH(fprofiler_ops.ops)
+	},
 	.entryfunc = &profile_graph_entry,
 	.retfunc = &profile_graph_return,
 };