[NTOS] Remove ROS-specific __NTOSKRNL__

See https://reactos.org/archives/public/ros-kernel/2004-June/003878.html
> In the source files one set of headers is included if
__NTDLL__ is defines and onother set if __NTOSKRNL__ is defines (dirty
workaround for our messy headers).

Author: HBelusca

ntoskrnl/include/internal/kd.h

@@ -28,7 +28,8 @@ KdPortPutByteEx(
 );
 
 /* SYMBOL ROUTINES **********************************************************/
-#ifdef __NTOSKRNL__
+
+#ifdef _NTOSKRNL_
 
 #ifdef KDBG
 # define KdbInit()                                  KdbpCliInit()

ntoskrnl/ntos.cmake

@@ -9,7 +9,6 @@ include_directories(
     ${REACTOS_SOURCE_DIR}/sdk/include/reactos/drivers)
 
 add_definitions(
-    -D__NTOSKRNL__
     -D_NTOSKRNL_
     -D_NTSYSTEM_
     -D_IN_KERNEL_

sdk/lib/drivers/ntoskrnl_vista/CMakeLists.txt

@@ -1,7 +1,7 @@
 remove_definitions(-D_WIN32_WINNT=0x502)
 add_definitions(-D_WIN32_WINNT=0x600)
 
-add_definitions(-DUNICODE -D_UNICODE -D__NTOSKRNL__ -D_NTOSKRNL_ -D_NTSYSTEM_)
+add_definitions(-DUNICODE -D_UNICODE -D_NTOSKRNL_ -D_NTSYSTEM_)
 
 include_directories(${REACTOS_SOURCE_DIR}/sdk/lib/rtl)
 

sdk/lib/drivers/rtlver/CMakeLists.txt

@@ -1,4 +1,4 @@
-add_definitions(-DUNICODE -D_UNICODE -D__NTOSKRNL__ -D_NTOSKRNL_ -D_NTSYSTEM_)
+add_definitions(-DUNICODE -D_UNICODE -D_NTOSKRNL_ -D_NTSYSTEM_)
 
 list(APPEND SOURCE
     rtl.c)