Fix PETSc deprecation warnings

Author: jwpeterson

src/solvers/petsc_dm_wrapper.C

@@ -74,15 +74,23 @@ void PetscDMWrapper::init_and_attach_petscdm(System & system, SNES & snes)
 
       // Build the PetscSection and attach it to the DM
       this->build_section(system, section);
+#if PETSC_VERSION_LESS_THAN(3,10,0)
       ierr = DMSetDefaultSection(dm, section);
+#else
+      ierr = DMSetSection(dm, section);
+#endif
       CHKERRABORT(system.comm().get(),ierr);
 
       // We only need to build the star forest if we're in a parallel environment
       if (system.n_processors() > 1)
         {
           // Build the PetscSF and attach it to the DM
           this->build_sf(system, star_forest);
+#if PETSC_VERSION_LESS_THAN(3,12,0)
           ierr = DMSetDefaultSF(dm, star_forest);
+#else
+          ierr = DMSetSectionSF(dm, star_forest);
+#endif
           CHKERRABORT(system.comm().get(),ierr);
         }
     }