Fix build with LLD by removing duplicate symbols already in IBVERBS_1.0.

[bdrewery]

Summary

Sponsored by: Dell EMC Isilon

Test Plan

Requires WITH_OFED=yes to build.

[emaste]

Can you confirm that GNU ld handles the duplicates in the same way (keeping the first definition)?

[bdrewery]

In D10352#214381, @emaste wrote:

Can you confirm that GNU ld handles the duplicates in the same way (keeping the first definition)?

From my amd64 build:

~/git/freebsd # readelf -a OBJ/contrib/ofed/usr.lib/libibverbs/libibverbs.so.1|grep @IBVERB|egrep '(ibv_get_device_list|ibv_free_device_list|ibv_get_device_name|ibv_get_device_guid|ibv_open_device|ibv_close_device)'
    72: 0000000000007dc0   166 FUNC    GLOBAL DEFAULT   12 ibv_get_device_guid@@IBVERBS_1.0 (2)
    73: 0000000000007e70   183 FUNC    GLOBAL DEFAULT   12 ibv_open_device@@IBVERBS_1.0 (2)
    83: 0000000000007da0    10 FUNC    GLOBAL DEFAULT   12 ibv_free_device_list@@IBVERBS_1.0 (2)
   105: 0000000000007f30   112 FUNC    GLOBAL DEFAULT   12 ibv_close_device@@IBVERBS_1.0 (2)
   106: 0000000000007db0    10 FUNC    GLOBAL DEFAULT   12 ibv_get_device_name@@IBVERBS_1.0 (2)
   109: 0000000000007ce0   186 FUNC    GLOBAL DEFAULT   12 ibv_get_device_list@@IBVERBS_1.0 (2)