Fix typo in comment on OpenSSL PEM password callback type name.

The type is called "pem_password_cb", not "pem_passwd_cb".

Author: Daniel Gustafsson
Discussion: https://www.postgresql.org/message-id/22108CF6-228B-45CF-9CDA-5C5F658DCC22@yesql.se

src/interfaces/libpq/fe-secure-openssl.c

@@ -1702,7 +1702,7 @@ PQsetSSLKeyPassHook(PQsslKeyPassHook_type hook)
 /*
  * Supply a password to decrypt a client certificate.
  *
- * This must match OpenSSL type pem_passwd_cb.
+ * This must match OpenSSL type pem_password_cb.
  */
 static int
 PQssl_passwd_cb(char *buf, int size, int rwflag, void *userdata)