mm, mempolicy: remove unneeded functions for UMA configs

Mempolicies only exist for CONFIG_NUMA configurations. Therefore, a
certain class of functions are unneeded in configurations where
CONFIG_NUMA is disabled such as functions that duplicate existing
mempolicies, lookup existing policies, set certain mempolicy traits, or
test mempolicies for certain attributes.

Remove the unneeded functions so that any future callers get a compile-
time error and protect their code with CONFIG_NUMA as required.

Signed-off-by: David Rientjes <[e-mail]>
Cc: KOSAKI Motohiro <[e-mail]>
Cc: Johannes Weiner <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/mempolicy.h

···
 {
 }
 
-static inline struct mempolicy *mpol_dup(struct mempolicy *old)
-{
-	return NULL;
-}
-
 struct shared_policy {};
-
-static inline int mpol_set_shared_policy(struct shared_policy *info,
-					struct vm_area_struct *vma,
-					struct mempolicy *new)
-{
-	return -EINVAL;
-}
 
 static inline void mpol_shared_policy_init(struct shared_policy *sp,
 						struct mempolicy *mpol)
···
 
 static inline void mpol_free_shared_policy(struct shared_policy *p)
 {
-}
-
-static inline struct mempolicy *
-mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
-{
-	return NULL;
 }
 
 #define vma_policy(vma) NULL
···
 {
 }
 
-static inline void mpol_fix_fork_child_flag(struct task_struct *p)
-{
-}
-
 static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
 				unsigned long addr, gfp_t gfp_flags,
 				struct mempolicy **mpol, nodemask_t **nodemask)
···
 }
 
 static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
-{
-	return false;
-}
-
-static inline bool mempolicy_nodemask_intersects(struct task_struct *tsk,
-			const nodemask_t *mask)
 {
 	return false;
 }
···
 	return 1;	/* error */
 }
 #endif
-
-static inline void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
-{
-}
 
 static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
 				 unsigned long address)