atm: fix a memory leak of vcc->user_back
In lec_arp_clear_vccs() only entry->vcc is freed, but vcc
could be installed on entry->recv_vcc too in lec_vcc_added().
This fixes the following memory leak:
unreferenced object 0xffff8880d9266b90 (size 16):
comm "atm2", pid 425, jiffies 4294907980 (age 23.488s)
hex dump (first 16 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 6b 6b 6b a5 ............kkk.
backtrace:
[<(____ptrval____)>] kmem_cache_alloc_trace+0x10e/0x151
[<(____ptrval____)>] lane_ioctl+0x4b3/0x569
[<(____ptrval____)>] do_vcc_ioctl+0x1ea/0x236
[<(____ptrval____)>] svc_ioctl+0x17d/0x198
[<(____ptrval____)>] sock_do_ioctl+0x47/0x12f
[<(____ptrval____)>] sock_ioctl+0x2f9/0x322
[<(____ptrval____)>] vfs_ioctl+0x1e/0x2b
[<(____ptrval____)>] ksys_ioctl+0x61/0x80
[<(____ptrval____)>] __x64_sys_ioctl+0x16/0x19
[<(____ptrval____)>] do_syscall_64+0x57/0x65
[<(____ptrval____)>] entry_SYSCALL_64_after_hwframe+0x49/0xb3
Cc: Gengming Liu <l.dmxcsnsbh@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8d9f73c0ad