remove reset_shared()

Hi hackers,

Is there any reason to keep reset_shared() around anymore?  It is now just
a wrapper function for CreateSharedMemoryAndSemaphores(), and AFAICT the
information in the comments is already covered by comments in the shared
memory code.  I think it's arguable that the name of the function makes it
clear that it might recreate the shared memory, but if that is a concern,
perhaps we could rename the function to something like
CreateOrRecreateSharedMemoryAndSemaphores().

I've attached a patch that simply removes this wrapper function.  This is
admittedly just nitpicking, so I don't intend to carry this patch further
if anyone is opposed.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com