lshal: Released column is now Y/N/?

Y: released
N: unreleased
?: unknown

Test: lshal_test

Change-Id: Ia9d840dd14d07bfbd362bcbc6fe42e58ec5d1d10
diff --git a/cmds/lshal/TableEntry.cpp b/cmds/lshal/TableEntry.cpp
index e8792a4..f390850 100644
--- a/cmds/lshal/TableEntry.cpp
+++ b/cmds/lshal/TableEntry.cpp
@@ -96,8 +96,11 @@
 std::string TableEntry::isReleased() const {
     static const std::string unreleased = Hash::hexString(Hash::kEmptyHash);
 
-    if (hash.empty() || hash == unreleased) {
-        return " "; // unknown or unreleased
+    if (hash.empty()) {
+        return "?";
+    }
+    if (hash == unreleased) {
+        return "N"; // unknown or unreleased
     }
     return "Y"; // released
 }