General help message cleanup

Many of the help messages were not really helpful; for example, many
commands that take no arguments would not print a correct synopsis
line, but "No additional help available." which is not exactly wrong,
but not helpful either.

Commit ``Make "usage" messages more helpful.'' changed this
partially. But it also became clear that lots of "Usage" and "Help"
messages (fields "usage" and "help" in struct cmd_tbl_s respective)
were actually redundant.

This patch cleans this up - for example:

Before:
	=> help dtt
	dtt - Digital Thermometer and Thermostat

	Usage:
	dtt         - Read temperature from digital thermometer and thermostat.

After:
	=> help dtt
	dtt - Read temperature from Digital Thermometer and Thermostat

	Usage:
	dtt

Signed-off-by: Wolfgang Denk <wd@denx.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/board/amcc/luan/luan.c b/board/amcc/luan/luan.c
index d2a3b9e..7d02d90 100644
--- a/board/amcc/luan/luan.c
+++ b/board/amcc/luan/luan.c
@@ -331,5 +331,5 @@ U_BOOT_CMD(
 	l2cache,   2,   1,     do_l2cache,
 	"enable or disable L2 cache",
 	"[on, off]\n"
-	"    - enable or disable L2 cache\n"
-	);
+	"    - enable or disable L2 cache"
+);