Staging: most: mostcore/core.c. Fix "missing static keyword" warnings

This is a patch to the mostcore/core.c file. It makes
several local functions and structures static to prevent global
visibility.

Signed-off-by: Adrian Remonda <adrianremonda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>