tracing: Add LATENCY_FS_NOTIFY to define if latency_fsnotify() is defined

With the coming addition of the osnoise tracer, the configs needed to
include the latency_fsnotify() has become more complex, and to keep the
declaration in the header file the same as in the C file, just have the
logic needed to define it in one place, and that defines LATENCY_FS_NOTIFY
which will be used in the C code.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -1690,8 +1690,7 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
 unsigned long __read_mostly	tracing_thresh;
 static const struct file_operations tracing_max_lat_fops;
 
-#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
-	defined(CONFIG_FSNOTIFY)
+#ifdef LATENCY_FS_NOTIFY
 
 static struct workqueue_struct *fsnotify_wq;
 

kernel/trace/trace.h

@@ -677,13 +677,13 @@ void update_max_tr_single(struct trace_array *tr,
 
 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
 	defined(CONFIG_FSNOTIFY)
+#define LATENCY_FS_NOTIFY
+#endif
 
+#ifdef LATENCY_FS_NOTIFY
 void latency_fsnotify(struct trace_array *tr);
-
 #else
-
 static inline void latency_fsnotify(struct trace_array *tr) { }
-
 #endif
 
 #ifdef CONFIG_STACKTRACE