Add a missing free() in read_flash()

Corresponding to flashrom svn r562.

Signed-off-by: Stephan Guilloux <stephan.guilloux@free.fr>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/flashrom.c b/flashrom.c
index c7e17d3..e9237a6 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -332,6 +332,7 @@
 
 	numbytes = fwrite(buf, 1, size, image);
 	fclose(image);
+	free(buf);
 	printf("%s.\n", numbytes == size ? "done" : "FAILED");
 	if (numbytes != size)
 		return 1;