crypto: reuse variable instead of reevaluation

Backport-PR-URL: nodejs#19114
PR-URL: nodejs#17735
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: tniessen

src/node_crypto.cc

@@ -3449,7 +3449,7 @@ void CipherBase::Init(const char* cipher_type,
                     nullptr,
                     reinterpret_cast<unsigned char*>(key),
                     reinterpret_cast<unsigned char*>(iv),
-                    kind_ == kCipher);
+                    encrypt);
 }
 
 
@@ -3518,7 +3518,7 @@ void CipherBase::InitIv(const char* cipher_type,
                     nullptr,
                     reinterpret_cast<const unsigned char*>(key),
                     reinterpret_cast<const unsigned char*>(iv),
-                    kind_ == kCipher);
+                    encrypt);
 }