Standardize command usage messages with cmd_usage()

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_fpga.c b/common/cmd_fpga.c
index dcbbc99..4abb86e 100644
--- a/common/cmd_fpga.c
+++ b/common/cmd_fpga.c
@@ -320,7 +320,7 @@
 
 static void fpga_usage (cmd_tbl_t * cmdtp)
 {
-	printf ("Usage:\n%s\n", cmdtp->usage);
+	cmd_usage(cmdtp);
 }
 
 /*