
The blk_getlength() function can return an error value if the image size cannot be determined. Check for this rather than ploughing on and trying to g_malloc0() a negative number. (Spotted by Coverity, CID 1288484.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>