Switch to now updated crates.io version of sc

The changes in the fork I was using have now been merged and released.

Author: tormol

Cargo.lock

@@ -27,5 +27,4 @@ lto = false # enabling LTO breaks objdump and requires other flags to ld
 panic = "abort"
 
 [dependencies]
-# fork of https://github.com/japaric/syscall.rs (sc 0.2.2) with updated feature flags
-sc = {git = "https://github.com/AgustinCB/syscall.rs/"}
+sc = "0.2.3"