[mlir][Linalg] NFC - Hotfix GenericLoopNestBuilder compilation error on older gcc (-fpermissive)

This fixes the error:
```
  mlir/include/mlir/Dialect/Linalg/Utils/Utils.h:72:3: error:   from definition of 'template<class LoopTy> mlir::edsc::GenericLoopNestRangeBuilder<LoopTy>::GenericLoopNestRangeBuilder(llvm::ArrayRef<mlir::edsc::ValueHandle*>, llvm::ArrayRef<mlir::Value>)' [-fpermissive]
    GenericLoopNestRangeBuilder(ArrayRef<edsc::ValueHandle *> ivs,
```

This was tested independently on a Docker image with gcc-5 by jpienaar@