[petsc-dev] plex example in master broken

[Barry Smith]

/sandbox/petsc/petsc.clone-3/arch-linux-pkgs-64idx/bin/mpicc -o ex3.o -c -fPIC -Wall -Wwrite-strings -Wno-strict-aliasing -Wno-unknown-pragmas -g3 -O0   -I/sandbox/petsc/petsc.clone-3/include -I/sandbox/petsc/petsc.clone-3/arch-linux-pkgs-64idx/include    `pwd`/ex3.c
/sandbox/petsc/petsc.clone-3/src/dm/impls/plex/examples/tests/ex3.c: In function ‘SetupSection’:
/sandbox/petsc/petsc.clone-3/src/dm/impls/plex/examples/tests/ex3.c:281:12: warning: passing argument 2 of ‘MPI_Comm_size’ from incompatible pointer type
     ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);