CVE-2026-74396: RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure

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

RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure

mlx5rumrupdatexlt() allocates and DMA maps an XLT buffer with mlx5rumrcreatexlt(). The buffer is released by the common cleanup path through mlx5rumrunmapfreexlt().

After mlx5odppopulatexlt() became fallible, its error path returned directly and skipped that cleanup. This leaks the XLT DMA mapping and buffer. If the emergency XLT page was used, it also leaves xltemergencypagemutex locked.

Break out of the loop so execution falls through the existing cleanup path.