xbps-create: do not use FTW_MOUNT with nftw(3).

There's not much point in using FTW_MOUNT anyway because we don't care
if files are in another filesystem. This makes it work with musl
(which uses a different behaviour when FTW_MOUNT is set).

bin/xbps-create/main.c

@@ -354,7 +354,7 @@ process_xentry(const char *key, const char *mutable_files)
 static void
 process_destdir(const char *mutable_files)
 {
-	if (nftw(".", ftw_cb, 20, FTW_PHYS|FTW_MOUNT) != 0)
+	if (nftw(".", ftw_cb, 20, FTW_PHYS) != 0)
 		die("failed to process destdir files (nftw):");
 
 	/* Process regular files */