drm/ttm: Don't print error message if eviction was interrupted

Avoid printing an error message if eviction was interrupted by,
for example, the user pressing CTRL-C. That may happen if eviction
is waiting for something, like for example a free batch-buffer.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230307144621.10748-6-thomas.hellstrom@linux.intel.com