cbfstool: Fix leak in cbfs_image struct initialization

This patches a memory leak on every struct cbfs_image creation that
was introduced by c1d1fd850ee7b8e52bd2ea5064fab68ac0c27098. Since that
commit, the CBFS master header has been copied to a separate buffer so
that its endianness could be fixed all at once; unfortunately, this
buffer was malloc()'d but never free()'d. To address the issue, we
replace the structure's struct cbfs_header * with a struct cbfs_header
to eliminate the additional allocation.

Change-Id: Ie066c6d4b80ad452b366a2a95092ed45aa55d91f
Signed-off-by: Sol Boucher <solb@chromium.org>
Reviewed-on: http://review.coreboot.org/10130
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/util/cbfstool/cbfs_image.h b/util/cbfstool/cbfs_image.h
index 1c2b6fd..51d06dc 100644
--- a/util/cbfstool/cbfs_image.h
+++ b/util/cbfstool/cbfs_image.h
@@ -28,7 +28,7 @@
 
 struct cbfs_image {
 	struct buffer buffer;
-	struct cbfs_header *header;
+	struct cbfs_header header;
 };
 
 /* Given a pointer, serialize the header from host-native byte format