bpf, arm: Fix various typos in comments

Various spelling mistakes in comments. Detected with the help of
Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220318103729.157574-9-Julia.Lawall@inria.fr