network: Fix a bunch of double-frees

Missing secrets are freed by eap_send_agent_req() even in case of
failure, so it was erroneous to try to free them on error.

==1048== Invalid read of size 8
==1048==    at 0x1603EC: l_queue_clear (queue.c:101)
==1048==    by 0x1603B8: l_queue_destroy (queue.c:82)
==1048==    by 0x135328: network_connect_8021x (network.c:943)
==1048==    by 0x1354C4: network_connect (network.c:987)
==1048==    by 0x178DD2: _dbus_object_tree_dispatch (dbus-service.c:1690)
==1048==    by 0x16D32A: message_read_handler (dbus.c:285)
==1048==    by 0x166EC3: io_callback (io.c:123)
==1048==    by 0x165A1A: l_main_iterate (main.c:376)
==1048==    by 0x165B58: l_main_run (main.c:423)
==1048==    by 0x1102DA: main (main.c:458)
==1048==  Address 0x5461850 is 0 bytes inside a block of size 24 free'd
==1048==    at 0x4C2C13B: free (vg_replace_malloc.c:530)
==1048==    by 0x15ED03: l_free (util.c:136)
==1048==    by 0x1603C4: l_queue_destroy (queue.c:83)
==1048==    by 0x134BD5: eap_secret_request_free (network.c:719)
==1048==    by 0x134EF9: eap_send_agent_req (network.c:817)
==1048==    by 0x1352F7: network_connect_8021x (network.c:936)
==1048==    by 0x1354C4: network_connect (network.c:987)
==1048==    by 0x178DD2: _dbus_object_tree_dispatch (dbus-service.c:1690)
==1048==    by 0x16D32A: message_read_handler (dbus.c:285)
==1048==    by 0x166EC3: io_callback (io.c:123)
==1048==    by 0x165A1A: l_main_iterate (main.c:376)
==1048==    by 0x165B58: l_main_run (main.c:423)
2 files changed