pgsql: Be sure length limit passed to snprintf matches what malloc was

Log Message:
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Be sure length limit passed to snprintf matches what malloc was given.
Just paranoia ...

Modified Files:
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pgsql/src/bin/pg_ctl:
pg_ctl.c (r1.45 -> r1.46)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_ctl/pg_ctl.c.diff?r1=1.45&r2=1.46)