Fix memory leak from recent change to s_compress_value

Commit c85f34c cleaned up the function,
but missed an all-important efree(buffer) on the no-compression path.

Author: sodabrew

Diff for: php_memcached.c

@@ -892,6 +892,7 @@ zend_bool s_compress_value (php_memc_compression_type compression_type, zend_str
 	}
 
 	/* Original payload was not modified */
+	efree(buffer);
 	return 0;
 }