Fix typo (#357)

Author: mox692

README.md

@@ -68,7 +68,7 @@ RUSTFLAGS="--cfg loom" cargo test --test buggy_concurrent_inc --release
 Loom currently does not implement the full C11 memory model.
 Here is the (incomplete) list of unsupported features.
 * `SeqCst` accesses (e.g. `load`, `store`, ..):
-  They are are regarded as `AcqRel`. That is, they impose weaker
+  They are regarded as `AcqRel`. That is, they impose weaker
   synchronization, causing Loom to generate false alarms (not complete). See
   [#180](https://github.com/tokio-rs/loom/issues/180) for example. On the other
   hand, `fence(SeqCst)` is supported.

src/lib.rs

@@ -279,7 +279,7 @@
 //! an exhaustive check, and instead tell loom to prune out interleavings that are unlikely to
 //! reveal additional bugs. You do this by providing loom with a _thread pre-emption bound_. If you
 //! set such a bound, loom will check all possible executions that include **at most** `n` thread
-//! pre-emptions (where one thread is forcibly stopped and another one runs in its place. **In
+//! pre-emptions where one thread is forcibly stopped and another one runs in its place. **In
 //! practice, setting the thread pre-emption bound to 2 or 3 is enough to catch most bugs** while
 //! significantly reducing the number of possible executions.
 //!