Pragma to hide GCC warning on mkstemp return value not used.

I did it because I thing it is irrelevant, although I'm not 100% sure.

Beside creating a tersed filename, "mkstemp" also opens the temporary file,
returns its FD, but we don't care.  Later, Interpreter re-opens this file
while it hasn't been closed -- because we don't care about the FD returned
by mkstemp, what the warning warns me of.

I don't think it is dangerous, but I should investigate more.
For nowtimes, I'm close to a Customer Shipment and I want to make the less
changes as I can.