perf/core: Fix several typos in comments

Fix typos in a few functions' documentation comments.

Signed-off-by: Roy Ben Shlomo <royb@sentinelone.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: royb@sentinelone.com
Link: http://lore.kernel.org/lkml/20190920171254.31373-1-royb@sentinelone.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

kernel/events/core.c

@@ -2239,7 +2239,7 @@ static void __perf_event_disable(struct perf_event *event,
  *
  * If event->ctx is a cloned context, callers must make sure that
  * every task struct that event->ctx->task could possibly point to
- * remains valid.  This condition is satisifed when called through
+ * remains valid.  This condition is satisfied when called through
  * perf_event_for_each_child or perf_event_for_each because they
  * hold the top-level event's child_mutex, so any descendant that
  * goes to exit will block in perf_event_exit_event().
@@ -6054,7 +6054,7 @@ static void perf_sample_regs_intr(struct perf_regs *regs_intr,
  * Get remaining task size from user stack pointer.
  *
  * It'd be better to take stack vma map and limit this more
- * precisly, but there's no way to get it safely under interrupt,
+ * precisely, but there's no way to get it safely under interrupt,
  * so using TASK_SIZE as limit.
  */
 static u64 perf_ustack_task_size(struct pt_regs *regs)
@@ -6616,7 +6616,7 @@ void perf_prepare_sample(struct perf_event_header *header,
 
 	if (sample_type & PERF_SAMPLE_STACK_USER) {
 		/*
-		 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
+		 * Either we need PERF_SAMPLE_STACK_USER bit to be always
 		 * processed as the last one or have additional check added
 		 * in case new sample type is added, because we could eat
 		 * up the rest of the sample size.