Remove the dead store in EVP_DecryptFinal_ex

CLA: trivial

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Todd Short <todd.short@me.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24526)

crypto/evp/evp_enc.c

@@ -1034,8 +1034,7 @@ int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
         for (i = 0; i < n; i++)
             out[i] = ctx->final[i];
         *outl = n;
-    } else
-        *outl = 0;
+    }
     return 1;
 }