Fix a compilation error due to undefined MSDOS_FAT12.

Upstream-Status: Inappropriate [licensing]
We're tracking an old release of dosfstools due to licensing issues.

Signed-off-by: Scott Garman <scott.a.garman@intel.com>

--- dosfstools-2.10/dosfsck/boot.c.orig	2004-10-15 08:51:42.394725176 -0600
+++ dosfstools-2.10/dosfsck/boot.c	2004-10-15 08:49:16.776862456 -0600
@@ -14,6 +14,9 @@
 #include "io.h"
 #include "boot.h"
 
+#ifndef MSDOS_FAT12
+#define MSDOS_FAT12 4084
+#endif
 
 #define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0)
     /* don't divide by zero */