km/ivm: fix string len check to support 7 char board names

km/ivm: fix string len check to support 7 char board names

The fanless boards now have a 7-digit (XXXXX-F) board name. This
triggers a border condition when reading this string in the IVM although
this string is smaller than the currenly read string size, but only by 1
character.

This patch corrects this by changing the size check condition for string
length. It is the same change that was done in the platform for this
same bug.

Signed-off-by: Valentin Longchamp <[email protected]>
cc: Holger Brunck <[email protected]>
cc: Stefan Bigler <[email protected]>