KVM: x86: fix TRACE_INCLUDE_PATH and remove -I. header search paths

The header search path -I. in kernel Makefiles is very suspicious;
it allows the compiler to search for headers in the top of $(srctree),
where obviously no header file exists.

The reason of having -I. here is to make the incorrectly set
TRACE_INCLUDE_PATH working.

As the comment block in include/trace/define_trace.h says,
TRACE_INCLUDE_PATH should be a relative path to the define_trace.h

Fix the TRACE_INCLUDE_PATH, and remove the iffy include paths.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/Makefile

@@ -2,10 +2,6 @@
 
 ccflags-y += -Iarch/x86/kvm
 
-CFLAGS_x86.o := -I.
-CFLAGS_svm.o := -I.
-CFLAGS_vmx.o := -I.
-
 KVM := ../../../virt/kvm
 
 kvm-y			+= $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \

arch/x86/kvm/trace.h

@@ -1465,7 +1465,7 @@ TRACE_EVENT(kvm_hv_send_ipi_ex,
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH arch/x86/kvm
+#define TRACE_INCLUDE_PATH ../../arch/x86/kvm
 #undef TRACE_INCLUDE_FILE
 #define TRACE_INCLUDE_FILE trace