libbb: make xchroot do a chdir("/") after chroot

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/util-linux/switch_root.c b/util-linux/switch_root.c
index db6ae35..a301b36 100644
--- a/util-linux/switch_root.c
+++ b/util-linux/switch_root.c
@@ -114,7 +114,7 @@
 	}
 	xchroot(".");
 	// The chdir is needed to recalculate "." and ".." links
-	xchdir("/");
+	/*xchdir("/"); - done in xchroot */
 
 	// If a new console specified, redirect stdin/stdout/stderr to it
 	if (console) {