blackfin: drop pte_file()

We've replaced remap_file_pages(2) implementation with emulation. Nobody
creates non-linear mapping anymore.

Signed-off-by: Kirill A. Shutemov <[e-mail]>
Cc: Steven Miao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/blackfin/include/asm/pgtable.h

···
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
 
-static inline int pte_file(pte_t pte)
-{
-	return 0;
-}
-
 #define set_pte(pteptr, pteval) (*(pteptr) = pteval)
 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)