Fix old references to chacha20.c/h that were renamed to charandom.*.

meson.build

@@ -9,7 +9,7 @@ dependency('threads')
 
 library(
     'randquik-chacha20',
-    'src/chacha20.c',
+    'src/charandom.c',
     build_by_default: true,
     c_args: ['-Wall', '-O3', '-march=native'],
 )

src/charandom.c

@@ -1,3 +1,3 @@
-#include "chacha20.h"
+#include "charandom.h"
 
 // Library build for Python CFFI to use