rust: init: add missing newline to pr_info! calls

[ Upstream commit 6933c106 ]

Several pr_info! calls in rust/kernel/init.rs (both in code examples
and macro documentation) were missing a newline, causing logs to
run together. This commit updates these calls to include a trailing
newline, improving readability and consistency with the C side.

Fixes: 6841d45a ("rust: init: add `stack_pin_init!` macro")
Fixes: 7f8977a7 ("rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`")
Fixes: d0fdc396 ("rust: init: add `PinnedDrop` trait and macros")
Fixes: 4af84c6a ("rust: init: update expanded macro explanation")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1139


Signed-off-by: Alban Kurti <kurti@invicto.ai>
Link: https://lore.kernel.org/r/20250206-printing_fix-v3-3-a85273b501ae@invicto.ai


[ Replaced Closes with Link since it fixes part of the issue. Added
  one more Fixes tag (still same set of stable kernels). - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>