Fix error message when attempting to xmh_realloc() 0 bytes. Though really, I'd expect it to perform a free(3) then, as the real realloc(3) does.
Fix error message when attempting to xmh_realloc() 0 bytes.
Though really, I'd expect it to perform a free(3) then, as the real
realloc(3) does.

mcr/nmh,mcr/nmh