rust: Use respectful terms.

There are mentions of whitelist/blacklist in the bindgen command line
which are blocked on
rust-lang/rust-bindgen#1812.

Bug: None
Test: None
Change-Id: I49fc99f2d7d74468a732d8d229886b1736ef335a

Author: jlucangelio

rust/minijail-sys/lib.rs

@@ -13,7 +13,7 @@
 // unsigned long int on amd64, which will end up being 32-bit on 32-bit platforms.
 //
 // As a workaround to let us commit these bindings and still use them on 32-bit platforms, the
-// bindgen invocation blacklists some of the generated fixed-width types and redefines them
+// bindgen invocation blocklists some of the generated fixed-width types and redefines them
 // manually as Rust fixed-width types.
 //
 // Generated in CrOS SDK chroot with: