samples/kprobes: Remove misleading comment

The example file supports many architectures not only x86 and PPC.

Signed-off-by: Marc Koderer <marc@koderer.com>
Cc: trivial@kernel.org
Link: https://lore.kernel.org/r/20201228060415.2194-1-marc@koderer.com


Signed-off-by: Jonathan Corbet <corbet@lwn.net>