mm: do not define PFN_SECTION_SHIFT if !CONFIG_SPARSEMEM

Do not define PFN_SECTION_SHIFT if !CONFIG_SPARSEMEM.
Signed-off-by: NDaniel Kiper <dkiper@net-space.pl>
Acked-by: NDave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h

@@ -605,10 +605,6 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 #define NODE_NOT_IN_PAGE_FLAGS
 #endif
 
-#ifndef PFN_SECTION_SHIFT
-#define PFN_SECTION_SHIFT 0
-#endif
-
 /*
  * Define the bit shifts to access each section.  For non-existent
  * sections we define the shift as 0; that plus a 0 mask ensures