emsmdb: fix deref through wrong type in exchange_emsmdb_dispatch

exch/emsmdb/main.cpp:285:14: runtime error: downcast of address which does not
point to an object of type 'ECDOASYNCCONNECTEX_IN'
note: object is of type 'ECDODISCONNECT_IN'
 1a 00 00 00  90 1f 80 99 a4 7f 00 00  02 00 00 00 6d 15 a2 59  9e ac 8b 4b 85 d2 fc a7  87 3b 1c e1
              ^~~~~~~~~~~~~~~~~~~~~~~
              vptr for 'ECDODISCONNECT_IN'

Fixes:  gromox-2.2-125-g64b2fb1e4

Author: jengelh

exch/emsmdb/main.cpp

@@ -280,7 +280,7 @@ static int exchange_emsmdb_dispatch(unsigned int opnum, const GUID *pobject,
 {
 	switch (opnum) {
 	case ecDoDisconnect: {
-		auto in  = static_cast<const ECDOASYNCCONNECTEX_IN *>(pin);
+		auto in  = static_cast<const ECDODISCONNECT_IN *>(pin);
 		auto out = ndr_stack_anew<ECDODISCONNECT_OUT>(NDR_STACK_OUT);
 		if (out == nullptr)
 			return DISPATCH_FAIL;