package/util-linux: revert logic regarding pam_selinux module

Leave pam_selinux enabled by default in su.pam and remove it from the
/etc/pam.d/su and /etc/pam.d/su-l files if libselinux is not selected.

This cosmetic change prevents leaving a misleading commented-out line
that references a PAM module that does not exist.

Signed-off-by: Carlos Santos <unixmania@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/util-linux/su.pam

@@ -7,9 +7,9 @@ account		required	pam_unix.so
 
 password	required	pam_unix.so nullok
 
-# session	required	pam_selinux.so close
+session		required	pam_selinux.so close
 session		required	pam_limits.so
 session		required	pam_env.so
 session		required	pam_unix.so
 session		optional	pam_lastlog.so
-# session	required	pam_selinux.so open
+session		required	pam_selinux.so open

package/util-linux/util-linux.mk

@@ -75,14 +75,14 @@ UTIL_LINUX_MAKE_OPTS += LIBS="$(UTIL_LINUX_LIBS)"
 ifeq ($(BR2_PACKAGE_LIBSELINUX),y)
 UTIL_LINUX_DEPENDENCIES += libselinux
 UTIL_LINUX_CONF_OPTS += --with-selinux
+else
+UTIL_LINUX_CONF_OPTS += --without-selinux
 define UTIL_LINUX_SELINUX_PAMFILES_TWEAK
 	$(foreach f,su su-l,
-		$(SED) 's/^# \(.*pam_selinux.so.*\)$$/\1/' \
+		$(SED) '/^.*pam_selinux.so.*$$/d' \
 			$(TARGET_DIR)/etc/pam.d/$(f)
 	)
 endef
-else
-UTIL_LINUX_CONF_OPTS += --without-selinux
 endif
 
 # Used by cramfs utils