staging: ramster: decrease foregin pers pages when count < 0
staging: ramster: decrease foregin pers pages when count < 0

commit 9a5c59687ad ("staging: ramster: Provide accessory functions for
counter decrease") forget decrease foregin pers pages, this patch fix
it.

Acked-by: Dan Magenheimer <017adcb67eaa7bc3974e87882304023d2fcc0db7@oracle.com>
Signed-off-by: Wanpeng Li <86d530c4a0b810dc887df1e4e084ed44c9b7acac@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

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