efi_loader: Make DisconnectController follow the EFI spec

commit 239d59a6 ("efi_loader: reconnect drivers on failure")
tried to fix the UninstallProtocol interface which must reconnect
any controllers it disconnected by calling ConnectController()
in case of failure. However, the reconnect functionality was wired in
efi_disconnect_all_drivers() instead of efi_uninstall_protocol().

As a result some SCT tests started failing.
Specifically, BBTestOpenProtocolInterfaceTest333CheckPoint3() test
 - Calls ConnectController for DriverImageHandle1
 - Calls DisconnectController for DriverImageHandle1 which will
   disconnect everything apart from TestProtocol4. That will remain
   open on purpose.
 - Calls ConnectController for DriverImageHandle2. TestProtocol4
   which was explicitly preserved was installed wth BY_DRIVER attributes.
   The new protocol will call DisconnectController since its attributes
   are BY_DRIVER|EXCLUSIVE, but TestProtocol4 will not be removed. The
   test expects EFI_ACCESS_DENIED which works fine.

   The problem is that DisconnectController, will eventually call
   EFI_DRIVER_BINDING_PROTOCOL.Stop(). But on the aforementioned test
   this will call CloseProtocol -- the binding protocol is defined in
   'DBindingDriver3.c' and the .Stop function uses CloseProtocol.
   If that close protocol call fails with EFI_NOT_FOUND, the current code
   will try to mistakenly reconnect all drivers and the subsequent tests
   that rely on the device being disconnected will fail.

Move the reconnection in efi_uninstall_protocol() were it belongs.

Fixes: commit 239d59a6 ("efi_loader: reconnect drivers on failure")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>