A selftest case for DAMON debugfs interface has a test for expected
failure.  To make the test output clean, hide the expected failure error
message.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/debugfs_rm_non_contexts.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh b/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
index 48b7af6b022c..f3ffeb1343cf 100644
--- a/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
+++ b/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
@@ -10,7 +10,7 @@ dmesg -C
 
 for file in "$DBGFS/"*
 do
-	echo "$(basename "$f")" > "$DBGFS/rm_contexts"
+	(echo "$(basename "$f")" > "$DBGFS/rm_contexts") &> /dev/null
 	if dmesg | grep -q BUG
 	then
 		dmesg
-- 
2.25.1