page allocator: slab: use nr_online_nodes to check for a NUMA platform
page allocator: slab: use nr_online_nodes to check for a NUMA platform

SLAB currently avoids checking a bitmap repeatedly by checking once and
storing a flag.  When the addition of nr_online_nodes as a cheaper version
of num_online_nodes(), this check can be replaced by nr_online_nodes.

(Christoph did a patch that this is lifted almost verbatim from)

Signed-off-by: Christoph Lameter <ef3ecccf258fa062c5c6521a4887d40541963af7@linux.com>
Signed-off-by: Mel Gorman <2f629c4d93e35c3d371f0463b040c6ef04a5c1e5@csn.ul.ie>
Cc: KOSAKI Motohiro <70a1d3ef3e17a2bb0f09a1b2e6c86f607ed1d6d9@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@cs.helsinki.fi>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Cc: Nick Piggin <3db79564e4bc2ada42ade8dfd09b5548e4fe6cdf@yahoo.com.au>
Cc: Dave Hansen <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <d03ac6c16933e58e5554872e134311ec0d08e0ed@hp.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

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