tools: imx8image: Fix handle leak

The handle "fd" was created in imx8image.c:249 by calling the "fopen"
 function and is lost in imx8image.c:282.
 Should close the 'fd' file descriptor before exiting the
 parse_cfg_file(image_t *param_stack, char *name) function.

Fixes: a2b96ece5be1 ("tools: add i.MX8/8X image support")
Signed-off-by: Mikhail Ilin <ilin.mikhail.ol@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/imx8image.c b/tools/imx8image.c
index 01e1486..395d5c6 100644
--- a/tools/imx8image.c
+++ b/tools/imx8image.c
@@ -279,6 +279,7 @@
 		}
 	}
 
+	fclose(fd);
 	return 0;
 }