lvm filter not generated correclty on rhel7

Since [1] filters for lvm are set up in /etc/cinder/lvm.conf file. The filter generation works fine on ubuntu, but on a rhel 7 (on x86 & s390) thing go wrong

Ubuntu generated filter:
filter = [ "a/dev/loop0/", "r/.*/" ]

RHEL7 generated filter
filter = [ "a/dev/loop0 stack-volumes-default/", "a/dev/loop1 stack-volumes-lvmdriver-1/", "r/.*/" ]

--> the rhel7 filter just does not make any sense. Seems like an error when parsing some input.

Root Cause (Example):
     IFS=';' read pv vg <<< $pv_info
rhel doesn't interpret the argument after the <<< operator as a single String
--> Solution: use quotation marks for the string argument: ... <<< "$pv_info"

[1] https://github.com/openstack-dev/devstack/commit/0b9e76f280208b5b5ad54bb6fbc4133e63037286