tool: fix pre-release.sh parameter check

It correctly checked the number of parameters, but continued
even if it did not match.

Author: psarna

tool/pre-release.sh

@@ -7,6 +7,7 @@
 
 if [[ "$#" != "1" ]]; then
     echo "Usage: $0 <release-number>"
+    exit 1
 fi
 
 for mode in "" "--enable-wasm-runtime" "--enable-wasm-runtime-dynamic"; do