Shouldn't execParallel.c null-terminate query_string in the parallel DSM?

Hi hackers,

I just saw some trailing garbage in my log file emanating from a
parallel worker when my query happened to be a BUFFERALIGNed length
(in this case 64 characters).  Did commit 4c728f382970 forget to make
sure the null terminator is copied?  See attached proposed fix.

-- 
Thomas Munro
http://www.enterprisedb.com