http: compression: brotli: Don't leak memory on error

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

Author: ac000

src/nxt_brotli.c

@@ -46,28 +46,33 @@ nxt_brotli_compress(nxt_http_comp_compressor_ctx_t *ctx, const uint8_t *in_buf,
                                      &in_len, &in_buf, &out_bytes, &out_buf,
                                      NULL);
     if (!ok) {
-        return -1;
+        goto out_err_free;
     }
 
     ok = BrotliEncoderCompressStream(brotli, BROTLI_OPERATION_FLUSH,
                                      &in_len, &in_buf, &out_bytes, &out_buf,
                                      NULL);
     if (!ok) {
-        return -1;
+        goto out_err_free;
     }
 
     if (last) {
         ok = BrotliEncoderCompressStream(brotli, BROTLI_OPERATION_FINISH,
                                          &in_len, &in_buf, &out_bytes,
                                          &out_buf, NULL);
         if (!ok) {
-            return -1;
+            goto out_err_free;
         }
 
         BrotliEncoderDestroyInstance(brotli);
     }
 
     return out_len - out_bytes;
+
+out_err_free:
+    BrotliEncoderDestroyInstance(brotli);
+
+    return -1;
 }