highmem: Remove unused functions

Nothing uses totalhigh_pages_dec() and totalhigh_pages_set().

Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

include/linux/highmem.h

···
 	atomic_long_inc(&_totalhigh_pages);
 }
 
-static inline void totalhigh_pages_dec(void)
-{
-	atomic_long_dec(&_totalhigh_pages);
-}
-
 static inline void totalhigh_pages_add(long count)
 {
 	atomic_long_add(count, &_totalhigh_pages);
-}
-
-static inline void totalhigh_pages_set(long val)
-{
-	atomic_long_set(&_totalhigh_pages, val);
 }
 
 void kmap_flush_unused(void);