KeyStore: stop using state()

Change-Id: Ib9a9af88a280a5442989a8199218a7ba82ce9e25
diff --git a/src/com/android/keychain/KeyChainService.java b/src/com/android/keychain/KeyChainService.java
index 1c41957..a2b44e8 100644
--- a/src/com/android/keychain/KeyChainService.java
+++ b/src/com/android/keychain/KeyChainService.java
@@ -111,7 +111,7 @@
             if (alias == null) {
                 throw new NullPointerException("alias == null");
             }
-            if (!isKeyStoreUnlocked()) {
+            if (!mKeyStore.isUnlocked()) {
                 throw new IllegalStateException("keystore is "
                         + mKeyStore.state().toString());
             }
@@ -123,10 +123,6 @@
             }
         }
 
-        private boolean isKeyStoreUnlocked() {
-            return (mKeyStore.state() == KeyStore.State.UNLOCKED);
-        }
-
         @Override public void installCaCertificate(byte[] caCertificate) {
             checkCertInstallerOrSystemCaller();
             try {