PR #9012 (b2e8240268) changed the output to
$(BUILD)/$(PROG) but the tests are still looking for $(PROG).
Also remove the now-unnecessary override of $(PROG) in the standard
variant.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
The xmlns attribute is required for older msbuild version (e.g. for
VS2015). Add it where needed, and reorder the attributes so all
files look the same.