wasi: remove unecessary null check

As reported by coverity the null check is
done after earlier code has already derefenced
options.envp. Either we should null check earlier
uses or this check is not necessary. Since options.envp
is created with new which should throw an
exception intead of returning null, it should
be safe to assume the null check is not required.

Signed-off-by: Michael Dawson <mdawson@devrus.com>

PR-URL: nodejs#42819
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

src/node_wasi.cc

@@ -236,11 +236,9 @@ void WASI::New(const FunctionCallbackInfo<Value>& args) {
     delete[] options.argv;
   }
 
-  if (options.envp != nullptr) {
-    for (uint32_t i = 0; options.envp[i]; i++)
-      free(const_cast<char*>(options.envp[i]));
-    delete[] options.envp;
-  }
+  for (uint32_t i = 0; options.envp[i]; i++)
+    free(const_cast<char*>(options.envp[i]));
+  delete[] options.envp;
 
   if (options.preopens != nullptr) {
     for (uint32_t i = 0; i < options.preopenc; i++) {