The r322210 change to pgrep's PID delimiting behaviour causes pgrep's default

The r322210 change to pgrep's PID delimiting behaviour causes pgrep's default
output to not include a trailing new line, which is a potential POLA violation
for existing consumers. Change pgrep to always emit a trailing new line on
completion of its output, regardless of the delimeter in use (which technically
is also a potential POLA violation for existing consumers that rely on the
pre-r322210 buggy behaviour, but a line has to be drawn somewhere).

PR:	221534
Submitted by:	kdrakehp zoho com
Reported by:	kdrakehp zoho com
MFC after:	1 week
X-MFC-with:	r322210