Fix typo in the Rustup 1.22.0 release post

Author: bjorn3

posts/2020-07-06-Rustup-1.22.0.md

@@ -31,7 +31,7 @@ This release is mostly related to internal rework and tweaks in UI messages.  It
 * Supporting running in a lower-memory mode on single-CPU systems, along with detecting any in-place soft-limits on memory consumption in an effort to reduce the chance you run out of RAM during an install on systems like Raspberry Pis
 * When we skip a `nightly` for missing-component reasons we now tell you all the missing components
 * We now tell you where overrides are coming from in `rustup show`
-* Added `riscv64gc-unknown-linux.gnu` version of `rustup`
+* Added `riscv64gc-unknown-linux-gnu` version of `rustup`
 * You can now specify multiple components when installing a toolchain more easily.  For example, if you wanted to install nightly with the `default` profile, but add the IDE support all in one go, you can now run
   ```
   rustup toolchain install --profile default --component rls,rust-analysis,rust-src nightly