move help text from include/usage.src.h to coreutils/*.c

Signed-off-by: Pere Orga <gotrunks@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index 53fb87a..ac0b0c3 100644
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -6,6 +6,12 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
+
+//usage:#define cksum_trivial_usage
+//usage:       "FILES..."
+//usage:#define cksum_full_usage "\n\n"
+//usage:       "Calculate the CRC32 checksums of FILES"
+
 #include "libbb.h"
 
 /* This is a NOEXEC applet. Be very careful! */