[mlir][linalg] Fix interchange initialization in fusion on tensors.

If no interchange vector is given initialize it with the identity permutation from 0 to number of loops.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D110249

mlir/lib/Dialect/Linalg/Transforms/FusionOnTensors.cpp

@@ -420,7 +420,7 @@ struct LinalgTileAndFuseTensorOps
         tileSizes.begin(), tileSizes.begin() + rootOp.getNumLoops());
     SmallVector<int64_t> rootInterchange =
         tileInterchange.empty()
-            ? llvm::to_vector<6>(llvm::seq<int64_t>(0, tileSizes.size()))
+            ? llvm::to_vector<6>(llvm::seq<int64_t>(0, rootOp.getNumLoops()))
             : SmallVector<int64_t>(tileInterchange.begin(),
                                    tileInterchange.begin() +
                                        rootOp.getNumLoops());