gluster: correct error message on failure to start remove brick

The variable type in error message for faliure to start remove brick
is changed from Gluster Volume to Gluster Brick(s). And action entry
for remove brick start which was missing earlier in one of the file
is updated

bug url: https://bugzilla.redhat.com/show_bug.cgi?id=1020282
Signed-off-by: ndarshan <dnarayan@redhat.com>
Change-Id: I10a55829a11fc19e1a43f38f45911e7aaf91d5b8