timestamping: fix example build

Fix Makefiles so that Documentation/networking/timestamping/timestamping.c
will build when using the CONFIG_BUILD_DOCSRC kconfig option.
(timestamping.c does not build currently with its simple Makefile.)

Also fix printf format warnings.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 2 deletions

diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile
index 2a1489fdc036..e79973443e9f 100644
--- a/Documentation/networking/timestamping/Makefile
+++ b/Documentation/networking/timestamping/Makefile
@@ -1,6 +1,13 @@
-CPPFLAGS = -I../../../include
+# kbuild trick to avoid linker error. Can be omitted if a module is built.
+obj- := dummy.o
 
-timestamping: timestamping.c
+# List of programs to build
+hostprogs-y := timestamping
+
+# Tell kbuild to always build the programs
+always := $(hostprogs-y)
+
+HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include
 
 clean:
         rm -f timestamping