tracing: Make ftrace_trace_stack() static

ftrace_trace_stack() is not called outside of trace.c. Make it a static
function.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -472,12 +472,20 @@ static inline void trace_access_lock_init(void)
 static void __ftrace_trace_stack(struct ring_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs);
+static void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
+			       int skip, int pc);
+
 #else
 static inline void __ftrace_trace_stack(struct ring_buffer *buffer,
 					unsigned long flags,
 					int skip, int pc, struct pt_regs *regs)
 {
 }
+static inline void ftrace_trace_stack(struct ring_buffer *buffer,
+				      unsigned long flags, int skip, int pc)
+{
+}
+
 #endif
 
 /* trace_flags holds trace_options default values */
@@ -1872,7 +1880,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
 
 }
 
-void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
+static void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 			int skip, int pc)
 {
 	if (!(trace_flags & TRACE_ITER_STACKTRACE))

kernel/trace/trace.h

@@ -611,20 +611,12 @@ void update_max_tr_single(struct trace_array *tr,
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
 #ifdef CONFIG_STACKTRACE
-void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
-			int skip, int pc);
-
 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 			    int pc);
 
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc);
 #else
-static inline void ftrace_trace_stack(struct ring_buffer *buffer,
-				      unsigned long flags, int skip, int pc)
-{
-}
-
 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 					  unsigned long flags, int pc)
 {