mm: use kmap_local_page in memzero_page

The commit message introducing the global memzero_page explicitly
mentions switching to kmap_local_page in the commit log but doesn't
actually do that.

Link: https://lkml.kernel.org/r/20210713055231.137602-3-hch@lst.de
Fixes: 28961998 ("iov_iter: lift memzero_page() to highmem.h")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/highmem.h

@@ -324,10 +324,10 @@ static inline void memcpy_to_page(struct page *page, size_t offset,
 
 static inline void memzero_page(struct page *page, size_t offset, size_t len)
 {
-	char *addr = kmap_atomic(page);
+	char *addr = kmap_local_page(page);
 	memset(addr + offset, 0, len);
 	flush_dcache_page(page);
-	kunmap_atomic(addr);
+	kunmap_local(addr);
 }
 
 #endif /* _LINUX_HIGHMEM_H */