name the /proc mount

The current mount code ends up generating a mount point like:
 /proc proc ro,nosuid,nodev,noexec,relatime 0 0

This confuses `mount` and users.  Give it a standard name of "proc".

Bug: None
Test: `mount` inside of minijail looks sane now
Change-Id: I771a32eea340cfe0a6bc9d21520057e0491de9f4
1 file changed