add a default weight_size

Author: jmitrevs

hls4ml/writer/quartus_writer.py

@@ -77,6 +77,7 @@ def print_array_to_cpp(self, var, layer, odir):
         rf = int(layer.get_attr('reuse_factor', 1))
         weight_header = '#ifdef __INTELFPGA_COMPILER__\n'
 
+        weight_size = 0
         if isinstance(layer, (Conv2D, Conv2DBatchnorm)):
             weight_size = (
                 layer.get_attr('impl_filt_height')