ANDROID: sdcardfs: Change current->fs under lock

Adjusted from previous version to add missing include

bug: 111641492

Change-Id: I321d83f5d599efb3abdfaf2f3a4900ac512beca6
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Git-commit: f6d0920c41a732be06d284177311b57335227bd1
Git-repo: https://android.googlesource.com/kernel/common/


Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>