fileio: fileio_size() can now fail

Part of making the fileio API more robust.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

src/flash/nand/fileio.c

@@ -180,7 +180,13 @@ COMMAND_HELPER(nand_fileio_parse_args, struct nand_fileio_state *state,
 		return retval;
 
 	if (!need_size)
-		state->size = fileio_size(&state->fileio);
+	{
+		int filesize;
+		retval = fileio_size(&state->fileio, &filesize);
+		if (retval != ERROR_OK)
+			return retval;
+		state->size = filesize;
+	}
 
 	*dev = nand;