Staging: lustre: Include header for functions prototypes

This patch includes the header lustre/include/lclient.h that declares
the functions lov_lsm_put and lov_read_and_clear_async_rc defined in
lov_object.c.

This eliminates warnings reported by sparse:
warning: symbol was not declared. Should it be static?

Signed-off-by: Darshana Padmadas <darshanapadmadas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>