Fix "environmental variable" to "environment variable" (#524)

Author: MisterDA

aes/src/lib.rs

@@ -106,7 +106,7 @@
 //! - `aes_compact`: reduce code size at the cost of slower performance
 //!   (affects only software backend).
 //!
-//! It can be enabled using `RUSTFLAGS` environmental variable
+//! It can be enabled using `RUSTFLAGS` environment variable
 //! (e.g. `RUSTFLAGS="--cfg aes_compact"`) or by modifying `.cargo/config`.
 //!
 //! [AES]: https://en.wikipedia.org/wiki/Advanced_Encryption_Standard

kuznyechik/src/lib.rs

@@ -16,7 +16,7 @@
 //! - `soft`: use software backend with big fused tables.
 //! - `compact_soft`: use software backend with small tables and slower performance.
 //!
-//! The flag can be enabled using `RUSTFLAGS` environmental variable
+//! The flag can be enabled using `RUSTFLAGS` environment variable
 //! (e.g. `RUSTFLAGS='--cfg kuznyechik_backend="soft"'`) or by modifying
 //! `.cargo/config`.
 //!

serpent/README.md

@@ -30,7 +30,7 @@ You can modify crate using the following configuration flags:
 
 - `serpent_no_unroll`: do not unroll rounds loop. Reduces binary size at the cost of slightly lower performance.
 
-The flag can be enabled using RUSTFLAGS environmental variable (e.g. RUSTFLAGS="--cfg serpent_no_unroll") or by modifying .cargo/config.
+The flag can be enabled using RUSTFLAGS environment variable (e.g. RUSTFLAGS="--cfg serpent_no_unroll") or by modifying .cargo/config.
 
 ## License