top(1): increase size of 'status' buffer

This corrects a warning issues by gcc9:
/srv/src/freebsd/head/usr.bin/top/machine.c:988:22: warning: '%5zu'
directive writing between 5 and 20 bytes into a
 region of size 15 [-Wformat-overflow=]
     sprintf(status, "?%5zu", state);

usr.bin/top/machine.c

@@ -920,7 +920,7 @@ format_next_process(caddr_t xhandle, char *(*get_userid)(int), int flags)
 	long cputime;
 	double pct;
 	struct handle *hp;
-	char status[16];
+	char status[22];
 	int cpu;
 	size_t state;
 	struct rusage ru, *rup;