It looks like this fixes the case where the statement is expanded to multiple statements in an if that isn't properly guarded. Does it actually fix the multiple statement warning? Regardless since it does fix one of the cases, seems fine.
10017 libilb: macro expands to multiple statements
Review Request #1303 — Created Nov. 30, 2018 and submitted
../common/ilb_sg.c: In function 'i_ilb_fillin_srvdata': ../common/libilb_impl.h:79:2: error: macro expands to multiple statements [-Werror=multistatement-macros] bzero(_i, sizeof (*(_i))); \ ^~~~~ ../common/ilb_sg.c:430:3: note: in expansion of macro 'IP_COPY_CLI_2_IMPL' IP_COPY_CLI_2_IMPL(&srv->sd_addr, &sgs->sgs_addr); ^~~~~~~~~~~~~~~~~~ ../common/ilb_sg.c:429:2: note: some parts of macro expansion are not guarded by this 'else' clause else ^~~~ cc1: all warnings being treated as errors