bpf, doc: Improve wording of docs

The phrase "dividing -1" is one I find confusing.  E.g.,
"INT_MIN dividing -1" sounds like "-1 / INT_MIN" rather than the inverse.
"divided by" instead of "dividing" assuming the inverse is meant.

Signed-off-by: Eslam Khafagy <eslam.medhat1993@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250607222434.227890-1-eslam.medhat1993@gmail.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>