src: prefer false instead of bool zero

This commit updates node_crypto.cc VerifySpkac function to use false
instead of 0 for its return bool value i.

PR-URL: #20218
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node_crypto.cc

@@ -5148,7 +5148,7 @@ void GetCurves(const FunctionCallbackInfo<Value>& args) {
 
 
 bool VerifySpkac(const char* data, unsigned int len) {
-  bool i = 0;
+  bool i = false;
   EVP_PKEY* pkey = nullptr;
   NETSCAPE_SPKI* spki = nullptr;