keystore: remove unused using statement

Test: pass
Bug: 36099713
Change-Id: I8f7e1559ce2dafbffee3d7c36083bf9a6307917f
diff --git a/keystore/include/keystore/keymaster_tags.h b/keystore/include/keystore/keymaster_tags.h
index b347dbf..05a33cd 100644
--- a/keystore/include/keystore/keymaster_tags.h
+++ b/keystore/include/keystore/keymaster_tags.h
@@ -86,7 +86,6 @@
 
 using ::android::hardware::hidl_vec;
 using ::android::hardware::Return;
-using ::android::hardware::Status;
 
 // The following create the numeric values that KM_TAG_PADDING and KM_TAG_DIGEST used to have.  We
 // need these old values to be able to support old keys that use them.