[Bug 46348] rpcrt4/tests/ server.c shows uninitialized memory use in union_tests()

https://bugs.winehq.org/show_bug.cgi?id=46348

--- Comment #1 from Austin English  ---
Second one in the same test:
==19714== Syscall param writev(vector[...]) points to uninitialised byte(s)
==19714==    at 0x4356813: writev (writev.c:26)
==19714==    by 0x7BC75457: send_request (server.c:228)
==19714==    by 0x7BC76158: server_call_unlocked (server.c:288)
==19714==    by 0x7BC761AD: wine_server_call (server.c:321)
==19714==    by 0x7BC419E5: server_write_file (file.c:621)
==19714==    by 0x7BC43FCB: NtWriteFile (file.c:1229)
==19714==    by 0x552D016: rpcrt4_conn_np_write (rpc_transport.c:416)
==19714==    by 0x551F74C: rpcrt4_conn_write (rpc_binding.h:197)
==19714==    by 0x5520FD0: RPCRT4_SendWithAuth (rpc_message.c:850)
==19714==    by 0x5521CE2: RPCRT4_Send (rpc_message.c:1249)
==19714==    by 0x5522C8E: I_RpcSend (rpc_message.c:1813)
==19714==    by 0x5522F6E: I_RpcSendReceive (rpc_message.c:1926)
==19714==    by 0x54FFBFF: NdrSendReceive (ndr_clientserver.c:215)
==19714==    by 0x4A6B3E6: ip_test (server_c.c:5576)
==19714==    by 0x4A59939: union_tests (server.c:1120)
==19714==    by 0x4A5E4EB: run_tests (server.c:1613)
==19714==    by 0x4A5E9C4: client (server.c:1698)
==19714==    by 0x4A60399: func_server (server.c:2229)
==19714==    by 0x4A7AFD8: run_test (test.h:617)
==19714==    by 0x4A7BA16: main (test.h:701)
==19714==  Address 0x4928c10 is 24 bytes inside a recently re-allocated block
of size 100 alloc'd
==19714==    at 0x7BC483AD: notify_alloc (heap.c:260)
==19714==    by 0x7BC4B8D1: RtlAllocateHeap (heap.c:1726)
==19714==    by 0x5521086: RPCRT4_SendWithAuth (rpc_message.c:809)
==19714==    by 0x5521CE2: RPCRT4_Send (rpc_message.c:1249)
==19714==    by 0x5522C8E: I_RpcSend (rpc_message.c:1813)
==19714==    by 0x5522F6E: I_RpcSendReceive (rpc_message.c:1926)
==19714==    by 0x54FFBFF: NdrSendReceive (ndr_clientserver.c:215)
==19714==    by 0x4A6B3E6: ip_test (server_c.c:5576)
==19714==    by 0x4A59939: union_tests (server.c:1120)
==19714==    by 0x4A5E4EB: run_tests (server.c:1613)
==19714==    by 0x4A5E9C4: client (server.c:1698)
==19714==    by 0x4A60399: func_server (server.c:2229)
==19714==    by 0x4A7AFD8: run_test (test.h:617)
==19714==    by 0x4A7BA16: main (test.h:701)
==19714==  Uninitialised value was created by a stack allocation
==19714==    at 0x4A595F7: union_tests (server.c:1069)
==19714==