RDMA/mlx5: Fix memory leak in GET_DATA_DIRECT_SYSFS_PATH handler

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix memory leak in GET_DATA_DIRECT_SYSFS_PATH handler The UVERBS_HANDLER(MLX5_IB_METHOD_GET_DATA_DIRECT_SYSFS_PATH) function allocates memory for the device path using kobject_get_path(). If the length of the device path exceeds the output buffer length, the function returns -ENOSPC but does not free the allocated memory, resulting in a memory leak. Add a kfree() call to the error path to ensure the allocated memory is properly freed. Compile tested only. Issue found using a prototype static analysis tool and code review.