correct jni.h include path

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
fix memcheck.h include path

memcheck.h was installed as /usr/include/valgrind/memcheck.h and
VALGRIND_CFLAGS has -I/usr/include.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>