pg_control_init() bug

Hello,

I noticed that pg_control_init() is failing an assertion on 13devel:

TRAP: FailedAssertion("(atti->attalign) == 's'", File: "heaptuple.c", Line: 160)
postgres: bossartn postgres [local] SELECT(ExceptionalCondition+0x55)[0x8e02b5]
postgres: bossartn postgres [local] SELECT(heap_compute_data_size+0x224)[0x486eb4]
postgres: bossartn postgres [local] SELECT(heap_form_tuple+0x82)[0x488262]
postgres: bossartn postgres [local] SELECT(pg_control_init+0x259)[0x902ca9]
postgres: bossartn postgres [local] SELECT(ExecMakeTableFunctionResult+0x345)[0x656a65]
postgres: bossartn postgres [local] SELECT[0x667e03]
postgres: bossartn postgres [local] SELECT(ExecScan+0x3ab)[0x6572db]
postgres: bossartn postgres [local] SELECT(standard_ExecutorRun+0x137)[0x64f097]
postgres: bossartn postgres [local] SELECT[0x7c5d8b]
postgres: bossartn postgres [local] SELECT(PortalRun+0x1d1)[0x7c71c1]
postgres: bossartn postgres [local] SELECT[0x7c34d1]
postgres: bossartn postgres [local] SELECT(PostgresMain+0x624)[0x7c4aa4]
postgres: bossartn postgres [local] SELECT[0x74109a]
postgres: bossartn postgres [local] SELECT(main+0x440)[0x69f220]
/lib64/libc.so.6(__libc_start_main+0xfd)[0x7fbb78309d1d]
postgres: bossartn postgres [local] SELECT[0x47b039]
2019-12-10 20:02:03.100 UTC [20859] LOG: server process (PID 20868) was terminated by signal 6: Aborted
2019-12-10 20:02:03.100 UTC [20859] DETAIL: Failed process was running: SELECT * FROM pg_control_init();
2019-12-10 20:02:03.100 UTC [20859] LOG: terminating any other active server processes

The attached patch seems to clear this up. I think this was missed in
2e4db241.

Nathan