Trivial comment fixes

This should have been part of
    2020-09-22 entropy: add & use _init(), _fill(), _done()
    3d8879d8ce0e27e0a0145e8f9948896dbab0f244
and
    2020-08-06 warnp: clean up with closelog()
    56b1c9192669add070e7cd73403d6e4c03c1efdd

libcperciva/util/warnp.c

@@ -17,7 +17,7 @@ static void
 warnp_atexit(void)
 {
 
-	/* Clean up writing to the syslog (if applicable).  */
+	/* Clean up writing to the syslog (if applicable). */
 	if (use_syslog)
 		closelog();
 
@@ -144,7 +144,7 @@ void
 warnp_syslog(int enable)
 {
 
-	/* Clean up writing to the syslog (if applicable).  */
+	/* Clean up writing to the syslog (if applicable). */
 	if (use_syslog && !enable)
 		closelog();