Oops, forgot to initiate the pointer after uses of CVec::new()

When the execution reaches the end of the main functions, they implicitly return a successful status.

Because we were previously converting the bytes in the format
string into Rust's char type and then printing that using the
format machinery, byte values that were not valid single-byte
UTF-8 characters failed to print correctly.  I found this while
trying to implement qsort() because the output of my test program
was mysteriously incorrect despite it working when I used glibc.