keystore: fix bug in clear_uid

Bug: 8566369
Change-Id: I92a37bb709bc491a305cf5b6a5e68b6ac1a8aa24
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index 482e21b..84f5794 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -2078,7 +2078,7 @@
                 }
             }
 
-            if (unlinkat(dirfd(dir), filename.string(), 0) && errno != ENOENT) {
+            if (unlinkat(dirfd(dir), file->d_name, 0) && errno != ENOENT) {
                 rc = ::SYSTEM_ERROR;
                 ALOGW("couldn't unlink %s", filename.string());
             }