[atomics.types.operations] note typo

[Dani-Hub]

The note in [atomics.types.operations] p25 (N4861) contains the following code example of the effects of the compare_exchange_strong operation:

if (memcmp(this, &expected, sizeof(*this)) == 0)
  memcpy(this, &desired, sizeof(*this));
else
  memcpy(expected, this, sizeof(*this));

This code is ill-formed, because expected in the else-branch is missing a leading & operator.