Dropped EIO_O_FSYNC as reported at #34 (comment)

Author: WyriHaximus

src/Eio/OpenFlagResolver.php

@@ -14,7 +14,6 @@ class OpenFlagResolver extends FlagResolver implements FlagResolverInterface
         'a' => EIO_O_APPEND,
         'c' => EIO_O_CREAT,
         'e' => EIO_O_EXCL,
-        'f' => EIO_O_FSYNC,
         'n' => EIO_O_NONBLOCK,
         'r' => EIO_O_RDONLY,
         't' => EIO_O_TRUNC,