objtool: Remove inat-tables.c when make clean

When build objtool on x86, the generated file inat-tables.c is in
arch/x86/lib instead of arch/x86, use the correct dir to remove it
when make clean.

$ cd tools/objtool
$ make
[...]
  GEN     arch/x86/lib/inat-tables.c
[...]
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/1652258270-6278-2-git-send-email-yangtiezhu@loongson.cn

tools/objtool/Makefile

@@ -63,7 +63,7 @@ $(LIBSUBCMD): fixdep FORCE
 clean:
 	$(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL)
 	$(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
-	$(Q)$(RM) $(OUTPUT)arch/x86/inat-tables.c $(OUTPUT)fixdep
+	$(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep
 
 FORCE: