Fixup a few stricter warnings

src/cfuhash.c

@@ -117,7 +117,7 @@ static u_int32_t
 hash_func(const void *key, size_t length) {
 	register size_t i = length;
 	register unsigned int hv = 0; /* could put a seed here instead of zero */
-	register const unsigned char *s = (unsigned char *)key;
+	register const unsigned char *s = (const unsigned char *)key;
 	while (i--) {
 		hv += *s++;
 		hv += (hv << 10);

src/cfulist.c

@@ -108,7 +108,7 @@ unlock_list(cfulist_t *list) {
 }
 
 static CFU_INLINE cfulist_entry *
-new_list_entry() {
+new_list_entry(void) {
 	return calloc(1, sizeof(cfulist_entry));
 }
 

src/cfuopt.c

@@ -285,10 +285,11 @@ _set_entry_val(cfuopt_list_entry_t *entry, const char *value) {
 	  case cfuopt_arg_string:
 		  if (entry->arg_data) *((char **)entry->arg_data) = cfustring_dup_c_str((char *)value);
 		  break;
+	  case cfuopt_arg_invalid:
+	  case cfuopt_arg_string_array:
 	  default:
 		  break;
 	}
-
 }
 
 typedef struct {