Btrfs: Update version.sh to v0.16

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/version.sh

@@ -6,7 +6,7 @@
 # Copyright 2008, Oracle
 # Released under the GNU GPLv2
  
-v="v0.15"
+v="v0.16"
 
 which hg > /dev/null
 if [ -d .hg ] && [ $? == 0 ]; then