sahara: Avoid closing invalid fd

In the event that no ramdump_path is provided to sahara_run() the
ramdump_dir will remain -1. For good hygiene avoid calling close() on
this invalid file descriptor.

Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>

sahara.c

@@ -492,7 +492,8 @@ int sahara_run(struct qdl_device *qdl, char *img_arr[], bool single_image,
 		}
 	}
 
-	close(ramdump_dir);
+	if (ramdump_dir >= 0)
+		close(ramdump_dir);
 
 	return done ? 0 : -1;
 }