staging: ramster: build ramster properly when CONFIG_OCFS2=m|y

Due to some conflicting debug vars, kernel build will warn when
CONFIG_RAMSTER=y and CONFIG_OCFS2=m and will fail when
CONFIG_RAMSTER=y and CONFIG_OCFS2=y (rare).

Rename ramster mlog vars to avoid the name conflict.

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>