Ignore EINTR on close(...) as there is nothing sane we can do.

Motivation:

If close(...) reports EINTR there is nothing sane we can do so it makes no sense to even report it. See also:

apple/swift-nio#217

Modifications:

Just ignore EINTR when calling close(...)

Result:

Less noise in the logs.

transport-native-unix-common/src/main/c/netty_unix_filedescriptor.c

@@ -79,7 +79,15 @@ static jint _read(JNIEnv* env, jclass clazz, jint fd, void* buffer, jint pos, ji
 // JNI Registered Methods Begin
 static jint netty_unix_filedescriptor_close(JNIEnv* env, jclass clazz, jint fd) {
  if (close(fd) < 0) {
- return -errno;
+ // There is really nothing "sane" we can do when EINTR was reported on close. So just ignore it and "assume"
+ // everything is fine == we closed the file descriptor.
+ //
+ // For more details see:
+ // - https://bugs.chromium.org/p/chromium/issues/detail?id=269623
+ // - https://lwn.net/Articles/576478/
+ if (errno != EINTR) {
+ return -errno;
+ }
  }
  return 0;
 }