keystore: Fix SoterTest issues

One of the SoterTest apk test is failing due to garbage value
seen when logging params.blob.data in keystore.

Change-Id: I8bb12bd85380c73822a7aaf1b0e0914e6b3a46a8
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index e9fa408..07212e9 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -2441,7 +2441,8 @@
                 {
                     uid_t callingUid = IPCThreadState::self()->getCallingUid();
                     Blob keyBlob;
-                    String8 name8(reinterpret_cast<const char*>(param.blob.data));
+                    String8 name8(reinterpret_cast<const char*>(param.blob.data),
+                                                        param.blob.data_length);
                     ResponseCode responseCode = mKeyStore->getKeyForName(&keyBlob,
                             name8, callingUid, TYPE_KEYMASTER_10);
                     if (responseCode != ::NO_ERROR) {