x86/build: Don't use $(LINUXINCLUDE) twice

The make variable KBUILD_CFLAGS contains $(LINUXINCLUDE). But the build
already picks up $(LINUXINCLUDE) from scripts/Makefile.lib. The net effect
is that the (long) list of include directories is used twice.

This is harmless but pointless. So stop using $(LINUXINCLUDE) twice.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1480077514-2586-1-git-send-email-pebolle@tiscali.nlSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/realmode/rm/Makefile

@@ -69,7 +69,7 @@ $(obj)/realmode.relocs: $(obj)/realmode.elf FORCE
 
 # ---------------------------------------------------------------------------
 
-KBUILD_CFLAGS	:= $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
+KBUILD_CFLAGS	:= $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
 		   -I$(srctree)/arch/x86/boot
 KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__
 GCOV_PROFILE := n