fix tiled vae blend extent range (#3384)

fix tiled vae bleand extent range

src/diffusers/models/autoencoder_kl.py

@@ -196,12 +196,14 @@ class AutoencoderKL(ModelMixin, ConfigMixin):
         return DecoderOutput(sample=decoded)
 
     def blend_v(self, a, b, blend_extent):
-        for y in range(min(a.shape[2], b.shape[2], blend_extent)):
+        blend_extent = min(a.shape[2], b.shape[2], blend_extent)
+        for y in range(blend_extent):
             b[:, :, y, :] = a[:, :, -blend_extent + y, :] * (1 - y / blend_extent) + b[:, :, y, :] * (y / blend_extent)
         return b
 
     def blend_h(self, a, b, blend_extent):
-        for x in range(min(a.shape[3], b.shape[3], blend_extent)):
+        blend_extent = min(a.shape[3], b.shape[3], blend_extent)
+        for x in range(blend_extent):
             b[:, :, :, x] = a[:, :, :, -blend_extent + x] * (1 - x / blend_extent) + b[:, :, :, x] * (x / blend_extent)
         return b