Fixed overlapping draw bug in snake game code.
Fixed overlapping draw bug in snake game code.

See: https://github.com/skilldrick/easy6502/pull/22



git-svn-id: dd14d189f2554b0b3f4c2209a95c13d2029e3fe8@989 96dfbd92-d197-e211-9ca9-00110a534b34

RyuKojiro/v6502