OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_OPENDIR

Add the VirtioFsFuseOpenDir() function, for sending the FUSE_OPENDIR
command to the Virtio Filesystem device.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-10-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

OvmfPkg/VirtioFsDxe/VirtioFsDxe.h

@@ -163,6 +163,13 @@ VirtioFsFuseInitSession (
   IN OUT VIRTIO_FS *VirtioFs
   );
 
+EFI_STATUS
+VirtioFsFuseOpenDir (
+  IN OUT VIRTIO_FS *VirtioFs,
+  IN     UINT64    NodeId,
+     OUT UINT64    *FuseHandle
+  );
+
 //
 // EFI_SIMPLE_FILE_SYSTEM_PROTOCOL member functions for the Virtio Filesystem
 // driver.