Properly remove failed tpu binNMUs from the result set

Signed-off-by: Adam D. Barratt <adam@adam-barratt.org.uk>

When undoing the addition to the result set of a binNMU from tpu, the package
name from the hint will end in ${arch}_tpu, not ${arch}, so we should check
for both cases.  At the same time, reverse the sense of the associated test
to make the logic more obvious.

britney.py

@@ -2308,9 +2308,9 @@ class Britney:
                 if pkg[0] != '-' and pkg_name in sources[suite]:
                     for p in sources[suite][pkg_name][BINARIES]:
                         binary, arch = p.split("/")
-                        if "/" in pkg and arch != pkg[pkg.find("/")+1:]: continue
-                        del binaries[arch][0][binary]
-                        self.systems[arch].remove_binary(binary)
+                        if '/' not in pkg or pkg.endswith("/%s" % (arch)) or pkg.endswith("/%s_tpu" % (arch)):
+                            del binaries[arch][0][binary]
+                            self.systems[arch].remove_binary(binary)
 
                 # undo the changes (binaries)
                 for p in undo['binaries'].keys():