Description of problem: [negative scenario]
rbd mirror pool peer remove returns 0 even for non existing peer's uuid

Version-Release number of selected component (if applicable):
14.2.22-49.el7cp

How reproducible:
Tried twice, faced twice

Steps to Reproduce: [negative scenario]
1. Configure rbd mirroring
2. try to remove non-existing peer's uuid and observe that command returns 0

Actual results:
Command returns zero even for non-existing peer is tried to be removed

# sudo rbd mirror pool peer remove test a-b-c-d
rbd: invalid uuid 'a-b-c-d'
# sudo rbd mirror pool peer remove test aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa
# echo $?
0
[root@DELL-R640-091 ~]# sudo rbd mirror pool info test
Mode: image
Site Name: site_a

Peer Sites: none

Expected results:
Command should error out saying there are no peers added with <uuid>