cmd_part: fix typo in part command help text

All the sub-commands start with the main command name, but it was
missing from one of the help texts.

<panto> typos fix.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Tom Rini <trini@ti.com>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
diff --git a/common/cmd_part.c b/common/cmd_part.c
index 1424854..c84bc27 100644
--- a/common/cmd_part.c
+++ b/common/cmd_part.c
@@ -82,7 +82,7 @@
 U_BOOT_CMD(
 	part,	5,	1,	do_part,
 	"disk partition related commands",
-	"uuid <interface> <dev>:<part>\n"
+	"part uuid <interface> <dev>:<part>\n"
 	"    - print partition UUID\n"
 	"part uuid <interface> <dev>:<part> <varname>\n"
 	"    - set environment variable to partition UUID\n"