Make runtime function return size_t

It returns sizeof(dirent_t), so I'm not sure why its return type is int.
It's only used once, and that usage immediately casts it to usize.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/rt/rust_builtin.c b/src/rt/rust_builtin.c
index af15bda4c3d..c2168d785b9 100644
--- a/src/rt/rust_builtin.c
+++ b/src/rt/rust_builtin.c
@@ -77,7 +77,7 @@ rust_readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) {
     return readdir_r(dirp, entry, result);
 }
 
-int
+size_t
 rust_dirent_t_size() {
     return sizeof(struct dirent);
 }