Fixing PETSC detection in installation

example/Numerics/Stoke_flow/1_3D_incompressible/Makefile

@@ -13,10 +13,10 @@ OBJ_PETSC = main_petsc.o
 all: stokes_3d_eigen stokes_3d_petsc
 
 stokes_3d_eigen: $(OBJ_EIGEN)
-	$(CC) -o $@ $^ $(CFLAGS) $(LIBS_PATH) $(LIBS)
+	$(CC) -fopenmp -o $@ $^ $(CFLAGS) $(LIBS_PATH) $(LIBS)
 
 stokes_3d_petsc: $(OBJ_PETSC)
-	$(CC) -o $@ $^ $(CFLAGS) $(LIBS_PATH) $(LIBS)
+	$(CC) -fopenmp -o $@ $^ $(CFLAGS) $(LIBS_PATH) $(LIBS)
 
 run: all
 	source $$HOME/openfpm_vars; mpirun -np 3 ./stokes_3d_eigen; mpirun -np 3 ./stokes_3d_petsc

m4/ax_petsc_lib.m4

@@ -102,8 +102,10 @@ AC_DEFUN([AX_LIB_PETSC], [
                         old_CC=$CC
                         old_CFLAGS=$CFLAGS
                         old_LDFLAGS=$LDFLAGS
-                        CFLAGS="-I$with_petsc/include $HDF5_INCLUDE $METIS_INCLUDE "
-                        LDFLAGS="-L$with_petsc/lib $HDF5_LDFLAGS  $HDF5_LIBS $METIS_LIB -lmetis "
+			AX_OPENMP([CFLAGS="$OPENMP_CFLAGS"
+				   LDFLAGS="$OPENMP_LDFLAGS"],[])
+                        CFLAGS="$CFLAGS -I$with_petsc/include $HDF5_INCLUDE $METIS_INCLUDE "
+                        LDFLAGS="$LDFLAGS -L$with_petsc/lib $HDF5_LDFLAGS  $HDF5_LIBS $METIS_LIB -lmetis "
 			CC=$CXX
 
                         AC_LANG_SAVE