[x86 setup] Newline after setup signature failure message

End the "No setup signature found..." with a newline (the puts
routine will automatically add a carriage return.)

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/i386/boot/header.S

@@ -280,4 +280,4 @@ die:
 	.section ".initdata", "a"
 setup_corrupt:
 	.byte	7
-	.string	"No setup signature found..."
+	.string	"No setup signature found...\n"