fix(mge/functional): del graph in __init__

GitOrigin-RevId: 4a62f39546

imperative/python/megengine/functional/__init__.py

@@ -17,4 +17,4 @@ from . import distributed  # isort:skip
 
 # delete namespace
 # pylint: disable=undefined-variable
-del elemwise, graph, loss, math, nn, quantized, tensor, utils  # type: ignore[name-defined]
+del elemwise, math, tensor, utils  # type: ignore[name-defined]

imperative/python/megengine/functional/nn.py

@@ -1024,7 +1024,6 @@ def matmul(
             format=format,
         )
 
-    inp1, inp2 = utils.convert_inputs(inp1, inp2)
     (result,) = apply(op, inp1, inp2)
     if shp is not None:
         result = result.reshape(shp)