efi_loader: correct notification of protocol installation

efi_loader: correct notification of protocol installation

When a protocol is installed the handle should be queued for the
registration key of each registered event. LocateHandle() should return the
first handle from the queue for the registration key and delete it from the
queue.

Implement the queueing.

Correct the selftest.

With the patch the UEFI SCT tests for LocateHandle() are passed without
failure.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>