Revert "ANDROID: vendor_hooks:vendor hook for mmput"

This reverts commit 8b19ed26.

The hook android_vh_mmput is not used by any vendor, so remove it to
help with merge issues with future LTS releases.

If this is needed by any real user, it can easily be reverted to add it
back and then the symbol should be added to the abi list at the same
time to prevent it from being removed again later.

Bug: 203756332
Bug: 238821038
Cc: xiaofeng <xiaofeng5@xiaomi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Idd40f231640723d2342a9dbac7e9206a800e82dd