vhost_user_fs: Move binary into vhost_user_fs crate

The binary is still built in the same location but the source code and
the dependencies for it come from the vhost_user_fs crate itself.

The binary will be built with:

`cargo build --all --bin vhost_user_fs` or just `cargo build --all`

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

Cargo.lock

@@ -1460,14 +1460,20 @@ name = "vhost_user_fs"
 version = "0.1.0"
 dependencies = [
  "bitflags 1.2.1",
+ "clap",
+ "epoll",
+ "futures",
  "libc",
  "log 0.4.8",
  "seccomp",
  "tempdir",
  "vhost",
+ "vhost_user_backend",
+ "virtio-bindings",
  "virtio-devices",
  "vm-memory",
  "vm-virtio",
+ "vmm-sys-util",
 ]
 
 [[package]]

vhost_user_fs/Cargo.toml

@@ -6,12 +6,18 @@ edition = "2018"
 
 [dependencies]
 bitflags = "1.1.0"
+clap = { version = "2.33.1", features=["wrap_help"] }
+epoll = ">=4.0.1"
+futures = { version = "0.3.5", features = ["thread-pool"] }
 libc = "0.2.71"
 log = "0.4.8"
 # Match the version in vmm
 seccomp = { git = "https://github.com/firecracker-microvm/firecracker", tag = "v0.21.1" }
-tempdir= "0.3.7"
+tempdir = "0.3.7"
+virtio-bindings = { version = "0.1", features = ["virtio-v5_0_0"]}
 virtio-devices = { path = "../virtio-devices" }
+vhost_rs = { git = "https://github.com/cloud-hypervisor/vhost", branch = "dragonball", package = "vhost", features = ["vhost-user-slave"] }
+vhost_user_backend = { path = "../vhost_user_backend"}
 vm-memory = "0.2.1"
 vm-virtio = { path = "../vm-virtio" }
-vhost_rs = { git = "https://github.com/cloud-hypervisor/vhost", branch = "dragonball", package = "vhost", features = ["vhost-user-slave"] }
+vmm-sys-util = "0.6.1"