Fix download link

Author: shantanualsi

changelogs/v0.11.0.md

@@ -17,7 +17,7 @@ Benchtool is also not released as a part of this version.
 
 ```console
 # download the binary (adapt os and arch as needed)
-$ curl -fSL -o "cortextool" "https://github.com/grafana/cortex-tools/releases/download/v0.11.0/cortextool_0.11.0_linux_x86_64"
+$ curl -fSL -o "cortextool" "https://github.com/grafana/cortex-tools/releases/download/v0.11.0/cortextool_v0.11.0_Linux_x86_64"
 
 # make it executable
 $ chmod a+x "cortextool"