Simplify configuration of ai_addr

Merge two separate config blocks for conditionally including ai_addr
in the addrinfo struct for unix/notbsd.

src/unix/notbsd/mod.rs

@@ -54,15 +54,13 @@ s! {
         pub ai_addrlen: socklen_t,
 
         #[cfg(any(target_os = "linux",
+                  target_os = "android",
                   target_os = "emscripten",
                   target_os = "fuchsia"))]
         pub ai_addr: *mut ::sockaddr,
 
         pub ai_canonname: *mut c_char,
 
-        #[cfg(target_os = "android")]
-        pub ai_addr: *mut ::sockaddr,
-
         pub ai_next: *mut addrinfo,
     }