[archivers] xzize: output file to same directory

Fix bug that caused the output file to always be generated in the
current working directory.

archivers/xzize.sh

@@ -36,7 +36,7 @@ test_extension()
         NEWEXTENSION="$3"
     fi
 
-    BASE="$(basename "$FILE" ."$EXTENSION")"
+    BASE="$(echo "$FILE" | sed "s/\.${EXTENSION}//")"
     if [ "$BASE" != "$FILE" ] ; then
         DEST="$BASE".$NEWEXTENSION
         return 0