mmcinfo: Fix help message

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Andy Fleming <afleming@gmail.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

common/cmd_mmc.c

@@ -144,8 +144,7 @@ int do_mmcinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 U_BOOT_CMD(
 	mmcinfo, 1, 0, do_mmcinfo,
 	"display MMC info",
-	"    - device number of the device to dislay info of\n"
-	""
+	"- dislay info of the current MMC device"
 );
 
 int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])