Ib restart hotfix (#1373)

Author: danieljvickers

src/simulation/m_collisions.fpp

@@ -148,7 +148,7 @@ contains
                         $:GPU_ATOMIC(atomic='update')
                         forces(pid2, l) = forces(pid2, l) - (normal_force(l) + tangental_force(l))
                         $:GPU_ATOMIC(atomic='update')
-                        torques(pid2, l) = torques(pid2, l) - torque(l)*patch_ib(pid2)%radius/patch_ib(pid1)%radius
+                        torques(pid2, l) = torques(pid2, l) + torque(l)*patch_ib(pid2)%radius/patch_ib(pid1)%radius
                     end do
                 end if
             end if

src/simulation/m_data_output.fpp

@@ -170,7 +170,7 @@ contains
         call s_create_directory(trim(case_dir) // '/restart_data')
         write (file_loc, '(A)') 'ib_state.dat'
         file_loc = trim(case_dir) // '/restart_data/' // trim(file_loc)
-        if (t_step_start /= 0) then
+        if (t_step_start > 0) then
             ! On restart, append to existing file to preserve history
             open (newunit=ib_state_unit, file=trim(file_loc), form='unformatted', access='stream', status='old', &
                   & position='append', iostat=ios)