shmem_team_destroy returns void

[davidozog]

shmem_team_destroy is supposed to return void but SOS returns an int.

[avincigu]

Looking into this, the change seems to be simple, unless I'm missing something big.

Here is a first pass:
#1168 (review)

I started a discussion on the only line of code that I think might be interesting.

[avincigu]

Fixed: #1168