glusterd : Coverity fix in __server_getspec

spec_fd handle should be closed in all the possible cases
CID : 1124768
Change-Id: I28390dc76a646a19258520570acef562b8d6fb1e
BUG: 789278
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/8091
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Gaurav Kumar Garg <ggarg@redhat.com>
Reviewed-by: Kaushal M <kaushal@redhat.com>