x86/build: Supress "Nothing to be done for ..." messages

When we build an already built kernel again, arch/x86/syscalls/Makefile
and arch/x86/tools/Makefile emits "Nothing to be done for ..."
messages.

Here is the command log:

$ make defconfig
[ snip ]
$ make
[ snip ]
$ make
make[1]: Nothing to be done for `all'. <-----
make[1]: Nothing to be done for `relocs'. <-----
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h

Besides not emitting those, "all" and "relocs" should be added to PHONY as well.

Signed-off-by: Masahiro Yamada <[e-mail]>
Acked-by: Peter Foley <[e-mail]>
Acked-by: Michal Marek <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/syscalls/Makefile

···
 
 targets	+= $(uapisyshdr-y) $(syshdr-y)
 
+PHONY += all
 all: $(addprefix $(uapi)/,$(uapisyshdr-y))
 all: $(addprefix $(out)/,$(syshdr-y))
+	@:

arch/x86/tools/Makefile

···
 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
 hostprogs-y	+= relocs
 relocs-objs     := relocs_32.o relocs_64.o relocs_common.o
+PHONY += relocs
 relocs: $(obj)/relocs
+	@: