Fix for floating point exception in check-portability.awk

[John Klos <john%ziaspace.com@localhost>]

Hi,

I was seeing these errors for various packages on netbsd-6 on VAX:

...
=> Checking for portability problems in extracted files
awk: floating point exception: Floating point overflow

 input record number 165261, file
 source line number 34
*** Error code 1

Stop.
...

The corresponding line calls split, apparently with either parameter 
empty. While it'd be nice to figure out where in awk this is and fix it 
there (I'll do that some other time), this fixes it for now:

        if (length(line) == 0 || length(word) == 0)
                return;

Is there a better way to do this?

John