ERROR: AddressSanitizer: heap-use-after-free on address 0x60c0001ca478 at pc 0x562dc173c5b9 bp 0x7ffe07f7a260 sp 0x7ffe07f7a258
    READ of size 4 at 0x60c0001ca478 thread T0
        0 0x562dc173c5b8 in ospf_lsa_lock ospfd/ospf_lsa.c:269
        1 0x562dc17242ec in ospf_flood_delayed_lsa_ack ospfd/ospf_flood.c:139
        2 0x562dc17242ec in ospf_flood ospfd/ospf_flood.c:553
        3 0x562dc1771bba in ospf_ls_upd ospfd/ospf_packet.c:1959
        4 0x562dc1771bba in ospf_read_helper ospfd/ospf_packet.c:2926
        5 0x562dc1771bba in ospf_read ospfd/ospf_packet.c:2957
        6 0x7f615e0dba5f in event_call lib/event.c:2005
        7 0x7f615e001781 in frr_run lib/libfrr.c:1252
        8 0x562dc170b171 in main ospfd/ospf_main.c:307
        9 0x7f615da2c249 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
        10 0x7f615da2c304 in __libc_start_main_impl ../csu/libc-start.c:360
        11 0x562dc170a9d0 in _start (/usr/lib/frr/ospfd+0x15e9d0)

    0x60c0001ca478 is located 56 bytes inside of 128-byte region [0x60c0001ca440,0x60c0001ca4c0)
    freed by thread T0 here:
        0 0x7f615e4b76a8 in __interceptor_free ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:52
        1 0x7f615e024478 in qfree lib/memory.c:136
        2 0x562dc173c976 in ospf_lsa_free ospfd/ospf_lsa.c:263
        3 0x562dc173ca7a in ospf_lsa_unlock ospfd/ospf_lsa.c:286
        4 0x562dc174eb11 in ospf_lsdb_delete_entry ospfd/ospf_lsdb.c:150
        5 0x562dc174f22e in ospf_lsdb_add ospfd/ospf_lsdb.c:173
        6 0x562dc1747fa5 in ospf_lsa_install ospfd/ospf_lsa.c:3071
        7 0x562dc17484db in ospf_summary_lsa_refresh ospfd/ospf_lsa.c:1436
        8 0x562dc174c116 in ospf_lsa_refresh ospfd/ospf_lsa.c:4050
        9 0x562dc174d236 in ospf_refresh_area_self_lsas ospfd/ospf_lsa.c:3826
        10 0x562dc17240d2 in ospf_flood ospfd/ospf_flood.c:533
        11 0x562dc1771bba in ospf_ls_upd ospfd/ospf_packet.c:1959
        12 0x562dc1771bba in ospf_read_helper ospfd/ospf_packet.c:2926
        13 0x562dc1771bba in ospf_read ospfd/ospf_packet.c:2957
        14 0x7f615e0dba5f in event_call lib/event.c:2005
        15 0x7f615e001781 in frr_run lib/libfrr.c:1252
        16 0x562dc170b171 in main ospfd/ospf_main.c:307
        17 0x7f615da2c249 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

    previously allocated by thread T0 here:
        0 0x7f615e4b83b7 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:77
        1 0x7f615e023b85 in qcalloc lib/memory.c:111
        2 0x562dc173c302 in ospf_lsa_new ospfd/ospf_lsa.c:193
        3 0x562dc173c5dc in ospf_lsa_new_and_data ospfd/ospf_lsa.c:212
        4 0x562dc1771192 in ospf_ls_upd_list_lsa ospfd/ospf_packet.c:1641
        5 0x562dc1771192 in ospf_ls_upd ospfd/ospf_packet.c:1726
        6 0x562dc1771192 in ospf_read_helper ospfd/ospf_packet.c:2926
        7 0x562dc1771192 in ospf_read ospfd/ospf_packet.c:2957
        8 0x7f615e0dba5f in event_call lib/event.c:2005
        9 0x7f615e001781 in frr_run lib/libfrr.c:1252
        10 0x562dc170b171 in main ospfd/ospf_main.c:307
        11 0x7f615da2c249 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Since we need to ack the lsa that was just freed, let's schedule the ack
before the free.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
(cherry picked from commit 6f6111b)