Taskstats: fix getdelays usage information

Add usage to getdelays.c. This patch was originally posted by Randy Dunlap
http://lkml.org/lkml/2007/3/19/168

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/accounting/getdelays.c

@@ -72,6 +72,16 @@ struct msgtemplate {
 
 char cpumask[100+6*MAX_CPUS];
 
+static void usage(void)
+{
+	fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
+			"[-m cpumask] [-t tgid] [-p pid]\n");
+	fprintf(stderr, "  -d: print delayacct stats\n");
+	fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
+	fprintf(stderr, "  -l: listen forever\n");
+	fprintf(stderr, "  -v: debug on\n");
+}
+
 /*
  * Create a raw netlink socket and bind
  */
@@ -227,7 +237,7 @@ int main(int argc, char *argv[])
 	struct msgtemplate msg;
 
 	while (1) {
-		c = getopt(argc, argv, "diw:r:m:t:p:v:l");
+		c = getopt(argc, argv, "diw:r:m:t:p:vl");
 		if (c < 0)
 			break;
 
@@ -277,7 +287,7 @@ int main(int argc, char *argv[])
 			loop = 1;
 			break;
 		default:
-			printf("Unknown option %d\n", c);
+			usage();
 			exit(-1);
 		}
 	}