chore: address review feedback on nonautonomous API changes

Agent-Logs-Url: https://github.com/ivan-pi/stiff3/sessions/67f692d9-43f0-4337-94d3-193b5edcdf71

Co-authored-by: ivan-pi <21085643+ivan-pi@users.noreply.github.com>

Author: Copilot

src/stiff3_solver.f90

@@ -306,8 +306,8 @@ subroutine fun_aug(naug,yi,fi)
       integer, intent(in) :: naug
       real(wp), intent(in) :: yi(naug)
       real(wp), intent(inout) :: fi(naug)
-      call fun(n,yi(1),yi(2:),fi(2:))
       fi(1) = 1.0_wp
+      call fun(n,yi(1),yi(2:),fi(2:))
     end subroutine
 
     subroutine jac_aug(naug,yi,dfi)

test/nonautonomous.f90

@@ -4,7 +4,7 @@ program nonautonomous
 
   implicit none
 
-  integer, parameter :: n = 1, nout = 100
+  integer, parameter :: n = 1, nprint = 100
   real(wp), parameter :: atol = 5.0e-6_wp
   real(wp) :: y(n), w(n), x0, x1, h0, eps, y_exact
 
@@ -15,7 +15,7 @@ program nonautonomous
   h0 = 1.0e-3_wp
   eps = 1.0e-8_wp
 
-  call stiff3(n,fun,jac,dfdx,out,nout,x0,x1,h0,eps,w,y)
+  call stiff3(n,fun,jac,dfdx,out,nprint,x0,x1,h0,eps,w,y)
 
   y_exact = 0.5_wp*(sin(x1) - cos(x1) + exp(-x1))
   if (abs(y(1)-y_exact) > atol) then