Fix swapiness sysctl set

Silly me copy-pasted the command incorrectly for change
I09974be88cc590cf9ffbd16db58c19131c9532aa; it needs an "=" in there

Change-Id: Icd853c670dfd9bd067f472203b38dd258d90e8ba

functions.sh

@@ -284,7 +284,7 @@ function fix_disk_layout {
     #
     # This sets swappiness low; we really don't want to be relying on
     # cloud I/O based swap during our runs
-    sudo sysctl -w vm.swappiness 10
+    sudo sysctl -w vm.swappiness=10
 }
 
 # Set up a project in accordance with the future state proposed by