Try to fix some DSA-related compiler warnings.
Commit
13df76a537cca3b8884911d8fdf7c89a457a8dd3 was overconfident
about how portable %016lx is. Some compilers complain because they
need %016llx, while platforms where DSA pointers are only 32 bits
get unhappy about using a 64-bit format for a 32-bit quantity.
Thomas Munro, per an off-list suggestion from me.