Revert "util-linux: add nsenter option"

This reverts commit 9f91d79601da42516752318beecfd080dc05aac9.

Not all toolchains have setns(), and the configure script automatically
enables nsenter if it does, so get rid of the explicit option.

See http://lists.busybox.net/pipermail/buildroot/2014-February/088669.html
for details.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/util-linux/Config.in

@@ -106,11 +106,6 @@ config BR2_PACKAGE_UTIL_LINUX_MOUNT
 	help
 	  Mount/unmount filesystems
 
-config BR2_PACKAGE_UTIL_LINUX_NSENTER
-	bool "nsenter"
-	help
-	  Enter namespaces (setns(2) frontend)
-
 config BR2_PACKAGE_UTIL_LINUX_PIVOT_ROOT
 	bool "pivot_root"
 	help

package/util-linux/util-linux.mk

@@ -62,7 +62,6 @@ UTIL_LINUX_CONF_OPT += \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_LOGIN_UTILS),--enable-last --enable-login --enable-su --enable-sulogin,--disable-last --disable-login --disable-su --disable-sulogin) \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_MESG),--enable-mesg,--disable-mesg) \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_MOUNT),--enable-mount,--disable-mount) \
-	$(if $(BR2_PACKAGE_UTIL_LINUX_NSENTER),--enable-nsenter,--disable-nsenter) \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_PARTX),,--disable-partx) \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_PIVOT_ROOT),--enable-pivot_root,--disable-pivot_root) \
 	$(if $(BR2_PACKAGE_UTIL_LINUX_RAW),--enable-raw,--disable-raw) \