Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_pci.c b/common/cmd_pci.c
index 67ff2fb..110415e 100644
--- a/common/cmd_pci.c
+++ b/common/cmd_pci.c
@@ -534,7 +534,7 @@
 
 	return 1;
  usage:
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 	return 1;
 }