Silence clang warning with explicit cast.
Silence clang warning with explicit cast.

The value of the computation itself should be unchanged.  The warning
text is below:

balance.c:23:9: warning: using integer absolute value function 'abs'
when argument is of floating point type [-Wabsolute-value]

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