linux-imx

btrfs: sanitizing ->fs_info, part 5

close_ctree() uses a weird mix of accesses to root->fs_info and
its value at the beginning of function stored in local variable.
Since ->fs_info *never* changes, let's just use the local variable
to avoid confusion.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>