svn 7520:[SNES] Fixed serial joystick reads to work as per docs.
This fixes a small regression introduced by Kale while fixing Suchie-Pai (rev. 5458). Now, Super Double Dragon and Super Star Wars Emprire Strikes Back recognize Start inputs again.
Unfortunately, this does not help Super Tetris 2 + Bombliss & Wordtris, whose inputs aren't recognized probably due to CPU timing problems...
EDIT: btw, this is another proof that few people actually use MESS for SNES: nobody noticed those games were broken since last summer... well, hopefully things will get better in future