s3: smbd: Fix fsp->base_fsp->fsp_name->fsp == fsp->base_fsp invarient in non_widelink...

s3: smbd: Fix fsp->base_fsp->fsp_name->fsp == fsp->base_fsp invarient in non_widelink_open().

Currently in master when we call into openat() in the VFS
we violate the invarient:

fsp->base_fsp->fsp_name->fsp == fsp->base_fsp.

The reason for this is subtle. Inside open.c:non_widelink_open()
we change the fsp->base_fsp to be relative to the new $cwd.

We do this by the following code in open.c:non_widelink_open():

        /* Also setup base_fsp to be relative to the new cwd */
        if (fsp->base_fsp != NULL) {
                base_smb_fname_rel = (struct smb_filename) {
                        .base_name = smb_fname_rel->base_name,
                };
                orig_base_fsp_name = fsp->base_fsp->fsp_name;
                fsp->base_fsp->fsp_name = &base_smb_fname_rel;
        }

Note that fsp->base_fsp->fsp_name now points at a
stack variable struct smb_filename, with smb_fname->fsp == NULL.

This fixes that problem by removing the horrid
stack based smb_filename and changing to use a
talloc'ed fsp->base_fsp->fsp_name, with
correctly linked fsp->base_fsp->fsp_name-> pointer.

Remove the selftest/knownfail.d/fruit_vfs_invariant
file as all vfs_fruit tests now pass again.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>