cbfstool: add bputs() to store a byte stream to a buffer

There was already a bgets() function which operates on a buffer to
copy a byte stream. Provide bputs() to store a byte stream to a
buffer, thus making the API symmetrical.

Change-Id: I6166f6b68eacb822da38c9da61a3e44f4c67136d
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/5366
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

util/cbfstool/common.h

@@ -112,6 +112,7 @@ struct xdr {
 
 /* xdr.c */
 extern struct xdr xdr_le, xdr_be;
-int bgets(struct buffer *input, void *output, size_t len);
+size_t bgets(struct buffer *input, void *output, size_t len);
+size_t bputs(struct buffer *b, const void *data, size_t len);
 
 #endif