more fixes*.* rename

nethack 3.0, nethack 2.2, and hack 1.0 did not use a three component
version numbering scheme so their corresponding fixes files shouldn't
do so either.  Change those from fixesX-Y-0.txt to fixesX-Y--.txt.

diff --git a/doc/fixes1-0-0.txt b/doc/fixes1-0--.txt
similarity index 100%
rename from doc/fixes1-0-0.txt
rename to doc/fixes1-0--.txt

diff --git a/doc/fixes2-2-0.txt b/doc/fixes2-2--.txt
similarity index 100%
rename from doc/fixes2-2-0.txt
rename to doc/fixes2-2--.txt

diff --git a/doc/fixes3-0-0.txt b/doc/fixes3-0--.txt
similarity index 100%
rename from doc/fixes3-0-0.txt
rename to doc/fixes3-0--.txt