Fix wrong comments

day09/ex1-c.c

@@ -1,4 +1,4 @@
-/* ex1-c: Advent2020 game, day 8/game 1
+/* ex1-c: Advent2020 game, day 9/game 1
  */
 
 #include <stdio.h>

day09/ex1.bash

@@ -1,6 +1,6 @@
 #!/bin/bash
 #
-# ex1.bash: Advent2020 game, day 8/game 1.
+# ex1.bash: Advent2020 game, day 9/game 1.
 
 CMD=${0##*/}
 shopt -s extglob

day09/ex2-c.c

@@ -1,4 +1,4 @@
-/* ex1-c: Advent2020 game, day 8/game 1
+/* ex2-c: Advent2020 game, day 9/game 2
  */
 
 #include <stdio.h>

day09/ex2.bash

@@ -1,6 +1,6 @@
 #!/bin/bash
 #
-# ex1.bash: Advent2020 game, day 8/game 1.
+# ex1.bash: Advent2020 game, day 9/game 2.
 
 CMD=${0##*/}
 shopt -s extglob