check: Suppress kmemleak scanning failures

kmemleak disables itself if an internal error has been encountered. If
this happens, any attempt to write into /sys/kernel/debug/kmemleak
triggers the error "Operation not permitted". Suppress this error
message instead of displaying it on stdout.

Signed-off-by: Bart Van Assche <[email protected]>
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>

Author: bvanassche

check

@@ -233,7 +233,7 @@ _check_kmemleak() {
 
 	((KMEMLEAK)) || return 0
 
-	echo scan > "$KMEMLEAK_FILE"
+	{ echo scan > "$KMEMLEAK_FILE"; } 2>/dev/null || return 0
 	sleep 1
 	kmemleak=$(cat "$KMEMLEAK_FILE")