CVE-2023-2283:pki_crypto: Remove unnecessary NULL check

Signed-off-by: Norbert Pocs <npocs@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

Author: Norbert Pocs

src/pki_crypto.c

@@ -3273,9 +3273,7 @@ int pki_verify_data_signature(ssh_signature signature,
     rc = SSH_OK;
 
 out:
-    if (ctx != NULL) {
-        EVP_MD_CTX_free(ctx);
-    }
+    EVP_MD_CTX_free(ctx);
     EVP_PKEY_free(pkey);
     return rc;
 }