Add missing backtick in E0569 explanation

diff --git a/src/librustc_error_codes/error_codes/E0569.md b/src/librustc_error_codes/error_codes/E0569.md
index 4cba0cf9c96baab174750a9090ad118deb4fabd8..2ca2b57ecace5f7d277fcaa6d19078f055a3c73c 100644 (file)
--- a/src/librustc_error_codes/error_codes/E0569.md
+++ b/src/librustc_error_codes/error_codes/E0569.md
@@ -1,5 +1,5 @@
 If an impl has a generic parameter with the `#[may_dangle]` attribute, then
-that impl must be declared as an `unsafe impl.
+that impl must be declared as an `unsafe impl`.
 
 Erroneous code example: