package/audit: Fix type output on log folder creation

Testing buildroot 2021.05 I observed that after first
boot I was having the following folders:

/context:
/system_u:object_r:auditd_log_t

The root of this problem turned to be a difference in the
output of $(selabel_lookup -b file -k /var/log/audit) called
by S02auditd that from this version on looks like:

$ selabel_lookup -b file -k /var/log/audit
Default context: system_u:object_r:auditd_log_t

This patch will cut it to retrieve the type piece only. Unfortunately,
audit has no options to create machine-readable output that is
guaranteed not to change, so that's the best we can do.

Signed-off-by: José Pekkarinen <jose.pekkarinen@unikie.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit e47832c8609ef88b949c5a93ed1810cece7342d1)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/audit/S02auditd

@@ -20,7 +20,7 @@ start(){
 	# the directory with SELinux permissions if possible
 	command -v selabel_lookup >/dev/null 2>&1
 	if [ $? = 0 ]; then
-		mkdir -p /var/log/audit -Z `selabel_lookup -b file -k /var/log/audit`
+		mkdir -p /var/log/audit -Z `selabel_lookup -b file -k /var/log/audit | cut -d ' ' -f 3`
 	else
 		mkdir -p /var/log/audit
 	fi