Update RustSBI to 0.2.0-alpha.8

Author: luojia65

Cargo.lock

@@ -6,7 +6,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-rustsbi = { version = "0.2.0-alpha.7" }
+rustsbi = { version = "0.2.0-alpha.8" }
 buddy_system_allocator = "0.8"
 lazy_static = { version = "1", features = ["spin_no_std"] }
 spin = "0.9"