core: fix l3cd comparison
NM_CMP_SELF(a, b) returns immediately if the objects are the same.
Fixes: cb292445 ('core: support compare flags in nm_l3_config_data_cmp_full()') Fixes-test: @dracut_NM_iSCSI_ibft_table
NM_CMP_SELF(a, b) returns immediately if the objects are the same.
Fixes: cb292445 ('core: support compare flags in nm_l3_config_data_cmp_full()') Fixes-test: @dracut_NM_iSCSI_ibft_table