Fix unused variable warning when !LIBMESH_HAVE_MPI
Fix unused variable warning when !LIBMESH_HAVE_MPI

BalticPinguin/libmesh,giorgiobornia/libmesh,benkirk/libmesh,pbauman/libmesh,salazardetroya/libmesh,vikramvgarg/libmesh,roystgnr/libmesh,benkirk/libmesh,vikramvgarg/libmesh,permcody/libmesh,aeslaughter/libmesh,svallaghe/libmesh,balborian/libmesh,balborian/libmesh,jiangwen84/libmesh,BalticPinguin/libmesh,cahaynes/libmesh,roystgnr/libmesh,friedmud/libmesh,jiangwen84/libmesh,svallaghe/libmesh,capitalaslash/libmesh,jiangwen84/libmesh,dmcdougall/libmesh,hrittich/libmesh,salazardetroya/libmesh,balborian/libmesh,salazardetroya/libmesh,pbauman/libmesh,hrittich/libmesh,hrittich/libmesh,giorgiobornia/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,vikramvgarg/libmesh,jiangwen84/libmesh,Mbewu/libmesh,svallaghe/libmesh,90jrong/libmesh,libMesh/libmesh,dschwen/libmesh,svallaghe/libmesh,permcody/libmesh,permcody/libmesh,aeslaughter/libmesh,jwpeterson/libmesh,friedmud/libmesh,pbauman/libmesh,cahaynes/libmesh,aeslaughter/libmesh,90jrong/libmesh,hrittich/libmesh,dmcdougall/libmesh,aeslaughter/libmesh,BalticPinguin/libmesh,dschwen/libmesh,aeslaughter/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,giorgiobornia/libmesh,salazardetroya/libmesh,permcody/libmesh,dknez/libmesh,dmcdougall/libmesh,dmcdougall/libmesh,hrittich/libmesh,aeslaughter/libmesh,roystgnr/libmesh,vikramvgarg/libmesh,capitalaslash/libmesh,balborian/libmesh,giorgiobornia/libmesh,coreymbryant/libmesh,hrittich/libmesh,coreymbryant/libmesh,jwpeterson/libmesh,benkirk/libmesh,roystgnr/libmesh,Mbewu/libmesh,dmcdougall/libmesh,permcody/libmesh,dknez/libmesh,balborian/libmesh,BalticPinguin/libmesh,dknez/libmesh,jiangwen84/libmesh,Mbewu/libmesh,90jrong/libmesh,karpeev/libmesh,giorgiobornia/libmesh,dknez/libmesh,90jrong/libmesh,Mbewu/libmesh,balborian/libmesh,hrittich/libmesh,karpeev/libmesh,90jrong/libmesh,hrittich/libmesh,friedmud/libmesh,salazardetroya/libmesh,salazardetroya/libmesh,jwpeterson/libmesh,cahaynes/libmesh,friedmud/libmesh,libMesh/libmesh,karpeev/libmesh,benkirk/libmesh,svallaghe/libmesh,jiangwen84/libmesh,friedmud/libmesh,jiangwen84/libmesh,svallaghe/libmesh,Mbewu/libmesh,cahaynes/libmesh,cahaynes/libmesh,jwpeterson/libmesh,pbauman/libmesh,pbauman/libmesh,cahaynes/libmesh,benkirk/libmesh,capitalaslash/libmesh,dschwen/libmesh,coreymbryant/libmesh,dmcdougall/libmesh,dknez/libmesh,BalticPinguin/libmesh,benkirk/libmesh,salazardetroya/libmesh,pbauman/libmesh,dschwen/libmesh,svallaghe/libmesh,hrittich/libmesh,capitalaslash/libmesh,dmcdougall/libmesh,dschwen/libmesh,roystgnr/libmesh,capitalaslash/libmesh,svallaghe/libmesh,dschwen/libmesh,90jrong/libmesh,capitalaslash/libmesh,karpeev/libmesh,coreymbryant/libmesh,karpeev/libmesh,libMesh/libmesh,coreymbryant/libmesh,giorgiobornia/libmesh,90jrong/libmesh,jiangwen84/libmesh,dschwen/libmesh,karpeev/libmesh,cahaynes/libmesh,vikramvgarg/libmesh,Mbewu/libmesh,vikramvgarg/libmesh,aeslaughter/libmesh,balborian/libmesh,dschwen/libmesh,pbauman/libmesh,pbauman/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,karpeev/libmesh,coreymbryant/libmesh,coreymbryant/libmesh,giorgiobornia/libmesh,90jrong/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,Mbewu/libmesh,libMesh/libmesh,permcody/libmesh,libMesh/libmesh,friedmud/libmesh,giorgiobornia/libmesh,dknez/libmesh,jwpeterson/libmesh,permcody/libmesh,Mbewu/libmesh,90jrong/libmesh,pbauman/libmesh,vikramvgarg/libmesh,aeslaughter/libmesh,friedmud/libmesh,friedmud/libmesh,balborian/libmesh,giorgiobornia/libmesh,coreymbryant/libmesh,Mbewu/libmesh,libMesh/libmesh,vikramvgarg/libmesh,benkirk/libmesh,dknez/libmesh,benkirk/libmesh,roystgnr/libmesh,roystgnr/libmesh,benkirk/libmesh,aeslaughter/libmesh,friedmud/libmesh,libMesh/libmesh,svallaghe/libmesh,vikramvgarg/libmesh,dmcdougall/libmesh,cahaynes/libmesh,dknez/libmesh,capitalaslash/libmesh,permcody/libmesh,balborian/libmesh,salazardetroya/libmesh,balborian/libmesh,libMesh/libmesh,karpeev/libmesh