This is the backwards compatibility code for MODULE_PARM, and moves
__MODULE_STRING() down to the graveyard at the bottom of module.h.

It's complicated by the fact that many modules place MODULE_PARM()
before the declaration (some do MODULE_PARM() for non-existant
variables, too).  To avoid breaking them, we have to do the name
lookups at load time, rather than just storing a pointer 8(

CONFIG_OBSOLETE_MODPARM is set to y without prompting: it's a useful
marker for deprecating in 2.7.