x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o

CFLAGS_REMOVE_*.o syntax is used to drop particular flags when
building objects from C files. It has no effect for assembly files.

vdso-note.o is compiled from the assembly file, vdso-note.S, hence
CFLAGS_REMOVE_vdso-note.o is meaningless.

Neither vvar.c nor vvar.S is found in the vdso directory. Since there
is no source file to create vvar.o, CFLAGS_REMOVE_vvar.o is also
meaningless.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191114154922.30365-1-yamada.masahiro@socionext.com