correct the compression_factor calculation

Author: dictcp

php_memcached.c

@@ -867,7 +867,8 @@ zend_bool s_compress_value (php_memc_compression_type compression_type, zend_str
 	}
 
 	/* This means the value was too small to be compressed, still a success */
-	if (compressed_size > (ZSTR_LEN(payload) * MEMC_G(compression_factor))) {
+	if (ZSTR_LEN(payload) < (compressed_size * MEMC_G(compression_factor))) {
+		MEMC_VAL_DEL_FLAG(*flags, MEMC_VAL_COMPRESSED);
 		efree (buffer);
 		return 1;
 	}