cbfs: drop file_cbfs_result declaration

It is not definded anywhere.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.gpk@gmx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/cbfs.h b/include/cbfs.h
index d915f94..d18001d 100644
--- a/include/cbfs.h
+++ b/include/cbfs.h
@@ -80,8 +80,6 @@
 	u32 attributes_offset;
 };
 
-extern enum cbfs_result file_cbfs_result;
-
 /**
  * file_cbfs_error() - Return a string describing the most recent error
  * condition.