There was a nasty sstate hash corruption issue occurring where the
fact the testimage bbclass was inherited meant that the checksum
changed due to testimage.bbclass being confused with image.bbclass.
This patch anchors the bbclass names to avoid this confusion.
(From OE-Core rev: 943a75a4f3b6877e4092dae14b59b7afef8cad3d)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>