physfssdl3 still refers to RWops in comments

[v1993]

A relatively minor documentation issue, but RWops are still mentioned in a few places in physfssdl3.h header, despite being renamed in SDL3. There's also a single mention in physfssdl3.c, incorrectly naming the function where the error occurs:

physfs/extras/physfssdl3.c

Line 134 in cac4490

SDL_SetError("NULL pointer passed to PHYSFSSDL3_makeRWops().");