shared/format-table: use goto to make code flow clear

shared/format-table: use goto to make code flow clear

gcc 9.3.0 "cc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0" with --optimization=1 was
not able to figure out that all cases are covered because r is either set in
the switch or type < _TABLE_DATA_TYPE_MAX.

But for a human reader this might also not be obvious: the cases are not in
exactly the same order as enum definitions, and it's a long list. By using the
goto, there should be no doubt, and we avoid checking the condition a second
time.