src/sd2.c: Fix a psf_binheader_writef usage bug

Unfortunately this bug cannot be found by the compiler and the tests
didn't find it either. It was found during work to improve the type
safety of calls to psf_binheader_writef.

Author: erikd

src/sd2.c

@@ -1,5 +1,5 @@
 /*
-** Copyright (C) 2001-2016 Erik de Castro Lopo <[email protected]>
+** Copyright (C) 2001-2017 Erik de Castro Lopo <[email protected]>
 ** Copyright (C) 2004 Paavo Jumppanen
 **
 ** This program is free software; you can redistribute it and/or modify
@@ -244,7 +244,7 @@ sd2_write_rsrc_fork (SF_PRIVATE *psf, int UNUSED (calc_length))
 	psf_binheader_writef (psf, "Eo2mm", make_size_t (0x50), 0, Sd2f_MARKER, lsf1_MARKER) ;
 
 	/* Very start of resource map. */
-	psf_binheader_writef (psf, "E444", make_size_t (rsrc.map_offset), rsrc.data_offset, rsrc.map_offset, rsrc.data_length) ;
+	psf_binheader_writef (psf, "E4444", make_size_t (rsrc.map_offset), rsrc.data_offset, rsrc.map_offset, rsrc.data_length) ;
 
 	/* These I don't currently understand. */
 	if (1)