Remove explicit unsafe from andoird accept4 wrapper.

Co-authored-by: Yuki Okushi <[email protected]>

Author: de-vri-es

src/unix/linux_like/android/mod.rs

@@ -2355,7 +2355,7 @@ f! {
     // directly. This workaround can be removed if the minimum version of
     // Android is bumped. When the workaround is removed, `accept4` can be
     // moved back to `linux_like/mod.rs`
-    pub unsafe fn accept4(
+    pub fn accept4(
         fd: ::c_int,
         addr: *mut ::sockaddr,
         len: *mut ::socklen_t,