cachefiles: Clean up some whitespace in trace header

Clean up some whitespace in the cachefiles trace header.

Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-3-dhowells@redhat.com


cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>