Fix RGBLINK incorrectly reading file stack nodes

This caused node IDs to mismatch, yielding possibly corrupted file stacks
Worst part is, the docs mentioned the reading order had to be reversed...

src/link/object.c

@@ -497,7 +497,7 @@ void obj_ReadFile(char const *fileName, unsigned int fileID)
 	if (!nodes[fileID].nodes)
 		err(1, "Failed to get memory for %s's nodes", fileName);
 	verbosePrint("Reading %u nodes...\n", nodes[fileID].nbNodes);
-	for (uint32_t i = 0; i < nodes[fileID].nbNodes; i++)
+	for (uint32_t i = nodes[fileID].nbNodes; i--; )
 		readFileStackNode(file, nodes[fileID].nodes, i, fileName);
 
 	/* This file's symbols, kept to link sections to them */