ANDROID: mnt: Fix freeing of mount data

Fix double free on error paths

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 65386954
Fixes: i1aaf05b35058 ("ANDROID: mnt: Add filesystem private data to mount points")
(cherry picked from commit b73dcc7a8799877207886c4c2fc8cd0848dfc464)
Git-Commit: 35d62d371cd2dacd281b2788d1fbf5a35ce3503b
Git-Repo: https://android.googlesource.com/kernel/common/


Change-Id: I1c25a175e87e5dd5cafcdcf9d78bf4c0dc3f88ef
Signed-off-by: Ankit Jain <jankit@codeaurora.org>