drm/buddy: Fix alloc_range() error handling code

In the Linux kernel, the following vulnerability has been resolved: drm/buddy: Fix alloc_range() error handling code Few users have observed display corruption when they boot the machine to KDE Plasma or playing games. We have root caused the problem that whenever alloc_range() couldn't find the required memory blocks the function was returning SUCCESS in some of the corner cases. The right approach would be if the total allocated size is less than the required size, the function should return -ENOSPC.