glusterd: Fix storing volumes on setting global opts

Glusterd would not store all the volumes when a global options were set.
When setting a global option, like 'nfs.*' options, glusterd used to
modify the volinfo for all the volumes, but would store only the volinfo
for the named volume. This lead to mismatch in the persisted and the
in-memory representation of those volumes, which lead to problems like
peers being rejected because of volume mismatches.

BUG: 1012400
Change-Id: I49903baaa4c93088d7c0d03553ccab37036b5426
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: http://review.gluster.org/6029
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>