os: Fix uname() error handling on sunos
os: Fix uname() error handling on sunos

The uname function can return any non-negative int to indicate success.

Strange, but that's how it is documented.  This also fixes a similar
buffer overflow in the even more unlikely event that info.release is
> 255 characters, similar to how 78c5de5 did for info.sysname.

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node