Bug#570838: lower the severity

[Prohle Peter <prohlep@math.bme.hu>]

Sorry, I was wrong.

I assumed, that the warning is concerning the subexpression (++i), 
but if we remove the <99 comparison, then the warning disappears, 
and hence the warning is concerning the unsused value of the coparison, 
namely the value of the non-last member of the comma expression 
is not used.

1: I suggest to lower the severity of this report #570838

2: I suggest to enhance the the warning string of the compiler to 
something like this:

"value of the non-last member of the comma expression is not used"

Regards,
	Peter PROHLE.