Avoid send-to-self in parallel_sync
Avoid send-to-self in parallel_sync

In addition to fixing the without-MPI cases, this should be an
optimization in every case.

dschwen/libmesh,roystgnr/libmesh,jwpeterson/libmesh,libMesh/libmesh,capitalaslash/libmesh,dschwen/libmesh,roystgnr/libmesh,capitalaslash/libmesh,libMesh/libmesh,roystgnr/libmesh,jwpeterson/libmesh,giorgiobornia/libmesh,roystgnr/libmesh,hrittich/libmesh,pbauman/libmesh,libMesh/libmesh,pbauman/libmesh,roystgnr/libmesh,dschwen/libmesh,hrittich/libmesh,pbauman/libmesh,capitalaslash/libmesh,hrittich/libmesh,pbauman/libmesh,giorgiobornia/libmesh,BalticPinguin/libmesh,90jrong/libmesh,roystgnr/libmesh,capitalaslash/libmesh,hrittich/libmesh,roystgnr/libmesh,hrittich/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,libMesh/libmesh,dschwen/libmesh,roystgnr/libmesh,dschwen/libmesh,libMesh/libmesh,giorgiobornia/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,giorgiobornia/libmesh,pbauman/libmesh,BalticPinguin/libmesh,90jrong/libmesh,BalticPinguin/libmesh,90jrong/libmesh,pbauman/libmesh,hrittich/libmesh,dschwen/libmesh,dschwen/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,dschwen/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,90jrong/libmesh,pbauman/libmesh,libMesh/libmesh,BalticPinguin/libmesh,giorgiobornia/libmesh,pbauman/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,90jrong/libmesh,BalticPinguin/libmesh,giorgiobornia/libmesh,hrittich/libmesh,90jrong/libmesh,hrittich/libmesh,libMesh/libmesh,pbauman/libmesh,hrittich/libmesh,libMesh/libmesh,90jrong/libmesh,90jrong/libmesh,jwpeterson/libmesh,90jrong/libmesh,giorgiobornia/libmesh