ANDROID: sdcardfs: make it use new .rename i_op

Since commit 2773bf00 ("fs: rename "rename2" i_op to "rename""),
syscall rename2 is merged with rename syscall and it broke sdcard_fs
build.

renameat2 syscall is the same as renameat with an added flags argument
and calling renameat2 with flags=0 is equivalent to calling renameat.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>