Update example/linalg/example_solve_pcg.f90

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: jalvesz

example/linalg/example_solve_pcg.f90

@@ -20,8 +20,8 @@ program example_solve_pcg
     x = 0._dp
     rhs = real( [0,0,5,0,0], kind=1._dp )
 
-    dirichlet = .false._1 
-    dirichlet([1,5]) = .true._1
+    dirichlet = .false._int8
+    dirichlet([1,5]) = .true._int8
 
     call solve_pcg(laplacian, rhs, x, tol=1.d-6, di=dirichlet)
     print *, x !> solution: [0.0, 2.5, 5.0, 2.5, 0.0]