docs: rust: remove spurious item in expect list

This list started as a "when to prefer `expect`" list, but at some point
during writing I changed it to a "prefer `expect` unless..." one. However,
the first bullet remained, which does not make sense anymore.

Thus remove it. In addition, fix nearby typo.

Fixes: 0486649 ("Documentation: rust: discuss `#[expect(...)]` in the guidelines")
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

Author: ojeda

Documentation/rust/coding-guidelines.rst

@@ -296,9 +296,7 @@ may happen in several situations, e.g.:
 It also increases the visibility of the remaining ``allow``\ s and reduces the
 chance of misapplying one.
 
-Thus prefer ``except`` over ``allow`` unless:
-
-- The lint attribute is intended to be temporary, e.g. while developing.
+Thus prefer ``expect`` over ``allow`` unless:
 
 - Conditional compilation triggers the warning in some cases but not others.