Revert "ANDROID: vfs: fix export symbol types"

This reverts commit efd3d77b as sdcardfs
is no longer in the tree.

Bug: 157700134
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I2148285290cd52b28b9282fc50c9acf015aa5a29