mm/um: use free_highmem_page() to free highmem pages into buddy system
mm/um: use free_highmem_page() to free highmem pages into buddy system

Use helper function free_highmem_page() to free highmem pages into
the buddy system.

Signed-off-by: Jiang Liu <68ee766e574f18b34b683085865827393efe88bd@huawei.com>
Cc: Jeff Dike <f9b6309e85863eba5d28138b6a0f35841ce976d0@addtoit.com>
Cc: Richard Weinberger <320bca71fc381a4a025636043ca86e734e31cf8b@nod.at>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs