improve install.sh and release ci (pingcap#2301)

.github/workflows/release-tiup.yaml

@@ -164,11 +164,6 @@ jobs:
 
           echo ${{ secrets.TIUP_COMP_KEY_PINGCAP }} | base64 -d > $TIUP_HOME/keys/private.json
 
-          # build the latest tiup to use for publish, this is a workaround and should
-          # be removed after this PR is merged and released
-          GOOS=linux GOARCH=amd64 make tiup
-          cp bin/tiup ${TIUP_BIN}
-
           # add a random delay before actually publishing, this can help reduce manifest conflict
           # when there are multiple jobs running in parallel
           sleep $[ ( $RANDOM % 10 ) ]s

install.sh

@@ -84,7 +84,7 @@ fi
 echo "Shell profile:  ${bold}$PROFILE${sgr0}"
 
 case :$PATH: in
-    *:$bin_dir:*) : "PATH already contains $bin_dir" ;;
+    *:$bin_dir:*) echo "PATH already contains $bin_dir" ;;
     *) printf '\nexport PATH=%s:$PATH\n' "$bin_dir" >> "$PROFILE"
         echo "$PROFILE has been modified to add tiup to PATH"
         echo "open a new terminal or ${bold}source ${PROFILE}${sgr0} to use it"