#351 div zero in voc.c

[treebacker]

There is a div zero in voc.c:334, functon read_samples.
Which crashes.
The trigger command: ./src/.libs/sox bug3 -n noiseprof /dev/null
In AddressSanitizer:

In gdb:

The crafted file is attached.

[Jan Starý]

$ sox ~/Downloads/sox-zero.voc -n noiseprof /dev/null
sox FAIL sox: `/Users/hans/Downloads/sox-zero.voc' format changed: Unsupported data format