Remove SO_NOSIGPIPE dummy variable on platforms that don't use it.

src/libstd/sys/unix/net.rs

@@ -28,14 +28,6 @@ use libc::SOCK_CLOEXEC;
 #[cfg(not(target_os = "linux"))]
 const SOCK_CLOEXEC: c_int = 0;
 
-// Another conditional constant for name resolution: Macos et iOS use
-// SO_NOSIGPIPE as a setsockopt flag to disable SIGPIPE emission on socket.
-// Other platforms do otherwise.
-#[cfg(target_vendor = "apple")]
-use libc::SO_NOSIGPIPE;
-#[cfg(not(target_vendor = "apple"))]
-const SO_NOSIGPIPE: c_int = 0;
-
 pub struct Socket(FileDesc);
 
 pub fn init() {}
@@ -89,9 +81,12 @@ impl Socket {
             let fd = FileDesc::new(fd);
             fd.set_cloexec()?;
             let socket = Socket(fd);
-            if cfg!(target_vendor = "apple") {
-                setsockopt(&socket, libc::SOL_SOCKET, SO_NOSIGPIPE, 1)?;
-            }
+
+            // macOS and iOS use `SO_NOSIGPIPE` as a `setsockopt`
+            // flag to disable `SIGPIPE` emission on socket.
+            #[cfg(target_vendor = "apple")]
+            setsockopt(&socket, libc::SOL_SOCKET, libc::SO_NOSIGPIPE, 1)?;
+
             Ok(socket)
         }
     }

src/libstd/sys/vxworks/net.rs

@@ -19,7 +19,6 @@ pub extern crate libc as netc;
 pub type wrlen_t = size_t;
 
 const SOCK_CLOEXEC: c_int = 0;
-const SO_NOSIGPIPE: c_int = 0;
 
 pub struct Socket(FileDesc);