mm: improve page_lock_anon_vma() comment
mm: improve page_lock_anon_vma() comment

A slightly more verbose comment to go along with the trickery in
page_lock_anon_vma().

Signed-off-by: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Reviewed-by: KOSAKI Motohiro <70a1d3ef3e17a2bb0f09a1b2e6c86f607ed1d6d9@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <634f508bd7c47cf0ee4126243675c3e598920fbc@jp.fujitsu.com>
Acked-by: Mel Gorman <2f629c4d93e35c3d371f0463b040c6ef04a5c1e5@csn.ul.ie>
Acked-by: Hugh Dickins <d3abdf3e2800e6cb849f11b81e6eb50b34d96431@google.com>
Cc: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>
Cc: David Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Cc: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>
Cc: Russell King <c2093e01fa868776d7876ac617ce6d2ac30cb904@arm.linux.org.uk>
Cc: Paul Mundt <38b52dbb5f0b63d149982b6c5de788ec93a89032@linux-sh.org>
Cc: Jeff Dike <f9b6309e85863eba5d28138b6a0f35841ce976d0@addtoit.com>
Cc: Richard Weinberger <320bca71fc381a4a025636043ca86e734e31cf8b@nod.at>
Cc: Tony Luck <e7984595ec0368ff920a7b3521dc7093683f6f26@intel.com>
Cc: Nick Piggin <24829078df5003d9dd1dd871ca2aeb0b1cf95ef4@kernel.dk>
Cc: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@gmail.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

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