kmsan: fix a stale comment in kmsan_save_stack_with_flags()

After commit 446ec83805 ("mm/page_alloc: use might_alloc()") and commit
84172f4bb7 ("mm/page_alloc: combine __alloc_pages and
__alloc_pages_nodemask"), the comment is no longer accurate.  Flag
'__GFP_DIRECT_RECLAIM' is clear enough on its own, so remove the comment
rather than update it.

Link: https://lkml.kernel.org/r/20230327034149.942-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/kmsan/core.c

@@ -73,7 +73,7 @@ depot_stack_handle_t kmsan_save_stack_with_flags(gfp_t flags,
 
 	nr_entries = stack_trace_save(entries, KMSAN_STACK_DEPTH, 0);
 
-	/* Don't sleep (see might_sleep_if() in __alloc_pages_nodemask()). */
+	/* Don't sleep. */
 	flags &= ~__GFP_DIRECT_RECLAIM;
 
 	handle = __stack_depot_save(entries, nr_entries, flags, true);