Fix some dependencies in tests
diff --git a/library/pkparse.c b/library/pkparse.c
index 2ecf143..a5de20b 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -255,7 +255,7 @@
                 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
 
     if( ( ret = rsa_check_pubkey( rsa ) ) != 0 )
-        return( ret );
+        return( POLARSSL_ERR_PK_INVALID_PUBKEY );
 
     rsa->len = mpi_size( &rsa->N );