appease apparmor 

get rid of following errors from /var/log/syslog on ubuntu (14.04 ?) 
Aug 20 12:11:41XXX kernel: [44551.172402] type=1400 audit(1408551101.021:100): apparmor="ALLOWED" operation="open" profile="/usr/sbin/mysqld" name="/mysql/data/dir/" pid=14432 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=105 ouid=105