virtfs fails to access contents of non-readable directories
Description of problem:
Attempting to access a directory inside a non-readable directory via virtfs fails.
Steps to reproduce:
On host:
1. `mkdir -p test/foo/bar`
2. `echo hello world >test/foo/bar/baz.txt`
3. `chmod -r test/foo`

The following works on host:

```
$ ls test
foo
$ ls test/foo
ls: cannot open directory 'test/foo': Permission denied
$ ls test/foo/bar
baz.txt
```

However on guest:

```
bash-5.1# ls /test/
foo
bash-5.1# ls /test/foo/
ls: cannot open directory '/test/foo/': Permission denied
bash-5.1# ls /test/foo/bar/
ls: cannot access '/test/foo/bar/': Permission denied
```
Additional information:
I am guessing virtfs attempts to check rights (via access?) on the directory itself when obtaining an inode to give to the guest, however not having read access doesn't mean something can't be executed, especially for directories.