input: Fix memory leak for hidp_connadd_req.
input: Fix memory leak for hidp_connadd_req.

If the struct input_device is destroyed while a hidp_connad_req
is pending, the input_device will be destroyed leaking the associated
memory.

==30790== 492 (168 direct, 324 indirect) bytes in 1 blocks are definitely lost in loss record 199 of 216
==30790==    at 0x4C29DB4: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==30790==    by 0x4E7FAE0: g_malloc0 (gmem.c:189)
==30790==    by 0x4378E4: hidp_add_connection (device.c:365)
==30790==    by 0x438055: input_device_connected (device.c:525)
==30790==    by 0x4380DA: interrupt_connect_cb (device.c:548)
==30790==    by 0x443508: connect_cb (btio.c:230)
==30790==    by 0x4E79D52: g_main_context_dispatch (gmain.c:2539)
==30790==    by 0x4E7A09F: g_main_context_iterate.isra.23 (gmain.c:3146)
==30790==    by 0x4E7A499: g_main_loop_run (gmain.c:3340)
==30790==    by 0x448CCC: main (main.c:583)

pkarasev3/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,mapfau/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,pkarasev3/bluez,silent-snowman/bluez,mapfau/bluez,pkarasev3/bluez,ComputeCycles/bluez,silent-snowman/bluez,ComputeCycles/bluez