glusterd/geo-rep: Fix glusterd crash in non-originator slave node.

Problem: glusterd crashes in non-originator slave node during geo-rep
         create push-pem.

Cause: In glusterd_op_copy_file, the value of the key "common_pem_contents"
       is freed explicitly even after dict_set is successful when it is
       taken cared by dict_free.

Solution: Free only in failure cases before dict_set.

Change-Id: I65b5f32ee2b946107ad279b1fe3d728ec699bc7e
BUG: 1159119
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/9018
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Poornima G <pgurusid@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>