mm/damon: remove unneeded damon_get_page()

After all damon_get_page() callers are converted to damon_get_folio(),
remove unneeded wrapper damon_get_page().

Link: https://lkml.kernel.org/r/20221230070849.63358-8-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/ops-common.h

@@ -8,13 +8,6 @@
 #include <linux/damon.h>
 
 struct folio *damon_get_folio(unsigned long pfn);
-static inline struct page *damon_get_page(unsigned long pfn)
-{
-	struct folio *folio = damon_get_folio(pfn);
-
-	/* when folio is NULL, return &(0->page) mean return NULL */
-	return &folio->page;
-}
 
 void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr);
 void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr);