ANDROID: vfs: fix export symbol types

In commit 4fd07efd90ca ("ANDROID: vfs: Add permission2 for filesystems
with per mount permissions") some new symbols were exported, but they
should have been set as _GPL symbols.

Fix this up by properly.

Bug: 35848445
Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4fb4b81f3b0a9d0b4c3aa69fffbc723762a629aa