Avoid non-ANSI function declarations

Sparse says things like:

	warning: non-ANSI function declaration of function 'calc_ttl'

Signed-off-by: John Keeping <john@keeping.me.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/filter.c b/filter.c
index 9f433db..ebf4937 100644
--- a/filter.c
+++ b/filter.c
@@ -72,7 +72,7 @@ static inline void hook_write(struct cgit_filter *filter, ssize_t (*new_write)(s
         filter_write = new_write;
 }
 
-static inline void unhook_write()
+static inline void unhook_write(void)
 {
         assert(filter_write != NULL);
         assert(current_write_filter != NULL);