Log Message:
Update to png 1.2.5:

* Changed png_error() to png_warning() about
  "Too much data" in pngpread.c and about
  "Extra compressed data" in pngrutil.c.
* Prevent png_ptr->pass from exceeding 7 in
  png_push_finish_row().
* Updated png.c and pnggccrd.c handling of return from
  png_mmx_support() [Doesn't apply to the package.]
* Only issue png_warning() about "Too much data" in
  pngpread.c when avail_in is nonzero.
* Relocated two misplaced PNGAPI lines in pngtest.c

Update submitted by Stefan Krüger in PR/18926.