style: Add void to function without arguments

After run `make CC=clang` we found the following problems:

    error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/ast.c b/src/ast.c
index 7bad020..d3e9a28 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -20,7 +20,7 @@
 #include <stdlib.h>
 
 ast_node_t *
-ast_node_new()
+ast_node_new(void)
 {
   ast_node_t *node = (ast_node_t *)malloc(sizeof(ast_node_t));
   if (node == NULL) {