simfs: Fix error reported by valgrind

==20365== Invalid read of size 8
==20365==    at 0x4B3501: sim_fs_free (simfs.c:114)
==20365==    by 0x493CEC: sim_remove (sim.c:2485)
==20365==    by 0x4703D7: modem_change_state (modem.c:410)
==20365==    by 0x470664: set_powered (modem.c:848)
==20365==    by 0x4706BA: __ofono_modem_shutdown (modem.c:2137)
==20365==    by 0x46F2C5: signal_cb (main.c:76)
==20365==    by 0x52F555E: g_io_unix_dispatch (giounix.c:166)
==20365==    by 0x52A0AAB: g_main_dispatch (gmain.c:2440)
==20365==    by 0x52A203B: g_main_context_dispatch (gmain.c:3013)
==20365==    by 0x52A2501: g_main_context_iterate (gmain.c:3091)
==20365==    by 0x52A2C98: g_main_loop_run (gmain.c:3299)
==20365==    by 0x46F0D3: main (main.c:243)
==20365==  Address 0x63ff998 is 8 bytes inside a block of size 16 free'd
==20365==    at 0x4C2612D: free (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==20365==    by 0x52AA4A1: g_free (gmem.c:263)
==20365==    by 0x52C433D: g_slice_free1 (gslice.c:907)
==20365==    by 0x52C58D0: g_slist_free_1 (gslist.c:192)
==20365==    by 0x52C5C5F: g_slist_remove (gslist.c:465)
==20365==    by 0x4B342A: sim_fs_context_free (simfs.c:192)
==20365==    by 0x4B3500: sim_fs_free (simfs.c:117)
==20365==    by 0x493CEC: sim_remove (sim.c:2485)
==20365==    by 0x4703D7: modem_change_state (modem.c:410)
==20365==    by 0x470664: set_powered (modem.c:848)
==20365==    by 0x4706BA: __ofono_modem_shutdown (modem.c:2137)
==20365==    by 0x46F2C5: signal_cb (main.c:76)

0 files changed, 0 insertions, 0 deletions