[NTOS:KD64] Fix freezes on first chance exception when KDBG is enabled and KdIgnoreUmExceptions is TRUE

This fixes the following use case:
- Execute 'kdbgctrl.exe -du'
- Execute 'kdbgctrl.exe -cu'
- See that last command never finishes

Author: hpoussin

ntoskrnl/kd64/kdtrap.c

@@ -318,7 +318,6 @@ KdIsThisAKdTrap(IN PEXCEPTION_RECORD ExceptionRecord,
                 IN PCONTEXT Context,
                 IN KPROCESSOR_MODE PreviousMode)
 {
-#ifdef _WINKD_
     /*
      * Determine if this is a valid debug service call and make sure that
      * it isn't a software breakpoint
@@ -335,8 +334,4 @@ KdIsThisAKdTrap(IN PEXCEPTION_RECORD ExceptionRecord,
         /* We don't have to handle it */
         return FALSE;
     }
-#else
-    /* KDBG has its own mechanism for ignoring user mode exceptions */
-    return FALSE;
-#endif
 }