tracing: Fix various typos in comments

Fix ~59 single-word typos in the tracing code comments, and fix
the grammar in a handful of places.

Link: https://lore.kernel.org/r/20210322224546.GA1981273@gmail.com
Link: https://lkml.kernel.org/r/20210323174935.GA4176821@gmail.com

Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 34dc1a7..632ef88 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -83,7 +83,7 @@ struct hwlat_sample {
 	u64			nmi_total_ts;	/* Total time spent in NMIs */
 	struct timespec64	timestamp;	/* wall time */
 	int			nmi_count;	/* # NMIs during this sample */
-	int			count;		/* # of iteratons over threash */
+	int			count;		/* # of iterations over thresh */
 };
 
 /* keep the global state somewhere. */
@@ -389,7 +389,7 @@ static int start_kthread(struct trace_array *tr)
 }
 
 /**
- * stop_kthread - Inform the hardware latency samping/detector kthread to stop
+ * stop_kthread - Inform the hardware latency sampling/detector kthread to stop
  *
  * This kicks the running hardware latency sampling/detector kernel thread and
  * tells it to stop sampling now. Use this on unload and at system shutdown.