message: Fix possible deadlocks
diff: @@ -307,9 +307,7 @@ pub extern "C" fn ferror(stream: &mut FILE) -> c_int {
  #[no_mangle]
  pub unsafe extern "C" fn fflush(stream: &mut FILE) -> c_int {
  flockfile(stream);
  -
  let ret = helpers::fflush_unlocked(stream);
  -
  funlockfile(stream);
  ret
  }
  @@ -362,6 +360,7 @@ pub extern "C" fn fgets(s: *mut c_char, n: c_int, stream: &mut FILE) -> *mut c_c
  {
  // We can't read from this stream
  if !stream.can_read() {
  + funlockfile(stream);
  return ptr::null_mut();
  }
  }
  @@ -408,8 +407,9 @@ pub extern "C" fn fgets(s: *mut c_char, n: c_int, stream: &mut FILE) -> *mut c_c
  #[no_mangle]
  pub extern "C" fn fileno(stream: &mut FILE) -> c_int {
  flockfile(stream);
  + let fd = stream.fd;
  funlockfile(stream);
  - stream.fd
  + fd
  }
  /// Lock the file
  @@ -483,6 +483,7 @@ pub extern "C" fn fread(ptr: *mut c_void, size: usize, nitems: usize, stream: &m
  flockfile(stream);
  if !stream.can_read() {
  + funlockfile(stream);
  return 0;
  }
  @@ -601,6 +602,7 @@ pub extern "C" fn fseeko(stream: &mut FILE, offset: off_t, whence: c_int) -> c_i
  }
  stream.write = None;
  if stream.seek(off, whence) < 0 {
  + funlockfile(stream);
  return -1;
  }
  stream.read = None;
  