tools/valgrind/asan: drop unnecessary py2 compatibility

This is blocked by https://crbug.com/1293351

Bug: 1275016
Change-Id: I57aea6e9d210fa42b646c7993917d71b246929e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3428262
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#971975}
NOKEYCHECK=True
GitOrigin-RevId: d63f7e92c4a34cb6dadeb79aea8c7f6d39c1071f
diff --git a/asan/asan_symbolize.py b/asan/asan_symbolize.py
index 1d45322..5f32de7 100755
--- a/asan/asan_symbolize.py
+++ b/asan/asan_symbolize.py
@@ -275,11 +275,7 @@
     if args.test_summary_json_file:
       symbolize_snippets_in_json(args.test_summary_json_file, loop)
     else:
-      # Process stdin.
-      if sys.version_info.major > 2:
-        asan_symbolize.logfile = CheckUTF8(sys.stdin)
-      else:
-        asan_symbolize.logfile = sys.stdin
+      asan_symbolize.logfile = CheckUTF8(sys.stdin)
       loop.process_logfile()