cros_fuzz: Fix bytes vs str for msan

Fix bytes vs str type issues when running with build_type msan

BUG=None
TEST=works with build_type msan

Change-Id: I1180db5456714221aacb3545915494f14a70206c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2155473
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Manoj Gupta <manojgupta@chromium.org>
diff --git a/scripts/cros_fuzz.py b/scripts/cros_fuzz.py
index f3c55a2..e2635b2 100644
--- a/scripts/cros_fuzz.py
+++ b/scripts/cros_fuzz.py
@@ -1102,7 +1102,8 @@
   # Check presence of "-fsanitize=memory" in CFLAGS.
   if options.build_type == BuildType.MSAN:
     cmd = ['portageq-%s' % options.board, 'envvar', 'CFLAGS']
-    cflags = cros_build_lib.run(cmd, capture_output=True).output.splitlines()
+    cflags = cros_build_lib.run(
+        cmd, capture_output=True, encoding='utf-8').stdout.splitlines()
     check_string = '-fsanitize=memory'
     if not any(check_string in s for s in cflags):
       logging.error(