[PATCH] remove vm_enough_memory double counting

From: Hugh Dickins <hugh@veritas.com>

Stop vm_enough_memory double counting total_swapcache_pages: it dates
from the days when we didn't free swap when freeing swapcache page.

mm/mmap.c

@@ -81,14 +81,6 @@ int vm_enough_memory(long pages)
 		free += nr_free_pages();
 		free += nr_swap_pages;
 
-		/*
-		 * This double-counts: the nrpages are both in the
-		 * page-cache and in the swapper space. At the same time,
-		 * this compensates for the swap-space over-allocation
-		 * (ie "nr_swap_pages" being too small).
-		 */
-		free += total_swapcache_pages;
-
 		/*
 		 * The code below doesn't account for free space in the
 		 * inode and dentry slab cache, slab cache fragmentation,