Fix GCC format-security errors and convert sprintfs.

With format-security errors turned on, GCC picks up the use of sprintf with
a format parameter not being a string literal.

Simple uses of sprintf are also converted to use strcpy.

Signed-off-by: Ben Whitten <ben.whitten@gmail.com>
Acked-by: Wolfgang Denk <wd@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/net/greth.c b/drivers/net/greth.c
index 088cb22..aa5d711 100644
--- a/drivers/net/greth.c
+++ b/drivers/net/greth.c
@@ -640,9 +640,9 @@
 
 	/* Make descriptor string */
 	if (greth->gbit_mac) {
-		sprintf(dev->name, "GRETH_10/100/GB");
+		strcpy(dev->name, "GRETH_10/100/GB");
 	} else {
-		sprintf(dev->name, "GRETH_10/100");
+		strcpy(dev->name, "GRETH_10/100");
 	}
 
 	/* initiate PHY, select speed/duplex depending on connected PHY */