staging: lustre: lmv: mark symbols static where possible

We get a few warnings when building kernel with W=1:
drivers/staging/lustre/lustre/lmv/lmv_obd.c:1640:1: warning: no previous prototype for 'lmv_locate_target_for_name' [-Wmissing-prototypes]
drivers/staging/lustre/lustre/lmv/lmv_obd.c:2421:5: warning: no previous prototype for 'lmv_read_page' [-Wmissing-prototypes]
....

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>