Documentation/sysctl/vm.txt: fix misleading code reference of overcommit_memory

The origin document references to cap_vm_enough_memory is because
cap_vm_enough_memory invoked __vm_enough_memory before and it no longer
does now.

Signed-off-by: Chun Chen <ramichen@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index a4482fc..f72370b 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -639,7 +639,7 @@
 The default value is 0.
 
 See Documentation/vm/overcommit-accounting and
-security/commoncap.c::cap_vm_enough_memory() for more information.
+mm/mmap.c::__vm_enough_memory() for more information.
 
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