fs-util: Handle dangling symlinks in openat_report_new()

fs-util: Handle dangling symlinks in openat_report_new()

openat() will always resolve symlinks, except if O_NOFOLLOW is passed
or O_CREAT|O_EXCL is passed. This means that if a dangling symlink is
passed to openat_report_new(), the first call to openat() will always
fail with ENOENT and the second call to openat() will always fail with
EEXIST.

Let's catch this case explicitly and fallback to creating the file with
just O_CREAT and assume we're the ones that created the file. We can't
resolve the symlink with chase() because this function is itself called
by chase() so we could end up in weird recursive calls if we'd try to do
so.