x86/vdso: Remove x32 intermediates during 'make clean'

The existing clean-files rule was missing vdsox32.so and
vdsox32.so.dbg.  We should really rename the intermediates to
allow a single rule to get them all.

Also-reported-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/7fa2ad4a63bc6f52e214125900d54165ef06cc10.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/vdso/Makefile

@@ -206,4 +206,4 @@ $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
 PHONY += vdso_install $(vdso_img_insttargets)
 vdso_install: $(vdso_img_insttargets) FORCE
 
-clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80* vdso64* vdso-image-*.c
+clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80* vdso64* vdso-image-*.c vdsox32.so*