sandbox: Prepare API change for files greater than 2GB

Change the internal sandbox functions to use loff_t for file offsets.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>

Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/common/board_f.c b/common/board_f.c
index d4d25d7..c6e38f3 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -287,7 +287,7 @@
 	struct sandbox_state *state = state_get_current();
 	const char *fname = state->fdt_fname;
 	void *blob;
-	ssize_t size;
+	loff_t size;
 	int err;
 	int fd;
 
@@ -300,10 +300,10 @@
 		return -EINVAL;
 	}
 
-	size = os_get_filesize(fname);
-	if (size < 0) {
+	err = os_get_filesize(fname, &size);
+	if (err < 0) {
 		printf("Failed to file FDT file '%s'\n", fname);
-		return -ENOENT;
+		return err;
 	}
 	fd = os_open(fname, OS_O_RDONLY);
 	if (fd < 0) {