drbd: replace kmap() with kmap_local_page() in receiver path

drbd: replace kmap() with kmap_local_page() in receiver path

Use kmap_local_page() instead of kmap() to avoid
CPU contention.

kmap() uses a global set of mapping slots that can cause contention
between multiple CPUs, while kmap_local_page() uses per-CPU slots
eliminating this contention. It also ensures non-sleeping operation
and provides better cache locality.

Convert kmap() to kmap_local_page() as it aligns with ongoing
kernel efforts to modernize kmap() usage for better multi-core
scalability.

Signed-off-by: Shi Hao <i.shihao.999@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>