[PATCH 1/2] image-host: add a check of the return value of snprintf.

[Hugo Cornelis]

Hi Simon, thanks for the feedback.

Yes, you were right.  I have split the function into two functions.
The patched is attached below (inline).

Some of the calls can be further 'logically' reordered, I believe, but
I don't know the program flow well enough to be sure.

One other 'inconsistency' is the occurence of a lookup based on the
string literal "iv-name-hint" while a few lines further in the source
code a lookup is performed based on a pre-processor define rather than
a string literal.  I have no clue about the reason of this difference.

Further comments are welcome.

Thanks, Hugo