CVE-2026-72244: gpu/buddy: bail out of try_harder when alignment cannot be honoured

In the Linux kernel, the following vulnerability has been resolved:

gpu/buddy: bail out of tryharder when alignment cannot be honoured

The tryharder contiguous fallback could return a range whose start offset did not match the caller's minblocksize. When a candidate's start is misaligned, realign it: free the misaligned run and reallocate exactly @size at the next lower minblocksize boundary. This keeps the returned size unchanged with no surplus to trim, and rejects the request only when no aligned candidate fits.

v2: align misaligned candidates down to minblocksize instead of bailing out, for both the RHS and LHS paths (Matthew).