Merge "Use fnctl.h instead of sys/fcntl.h for O_RDWR" am: 58dc9c0a14 am: 4e0f311453 am: 7af59b6b36 am: b7d6c5db3b

Original change: https://android-review.googlesource.com/c/platform/external/mdnsresponder/+/1797189

Change-Id: Ife9530a7e94038684ab6c6e24ba479dc1f57cf01