Split self.options.adt_arches once during initialization

For consistency with all other self.options.*_arches.

autopkgtest.py

@@ -535,7 +535,7 @@ class AutoPackageTest(object):
         self.log_verbose('Requested autopkgtests for %s, exclusions: %s' %
                          (['%s/%s' % i for i in packages], str(self.excludes)))
         for src, ver in packages:
-            for arch in self.britney.options.adt_arches.split():
+            for arch in self.britney.options.adt_arches:
                 for (testsrc, testver) in self.tests_for_source(src, ver, arch):
                     self.add_test_request(testsrc, testver, arch, src, ver)
 
@@ -572,7 +572,7 @@ class AutoPackageTest(object):
         # TODO: Once we support version constraints in AMQP requests, add them
         # arch →  (queue_name, [(pkg, params), ...])
         arch_queues = {}
-        for arch in self.britney.options.adt_arches.split():
+        for arch in self.britney.options.adt_arches:
             requests = []
             for pkg, verinfo in self.requested_tests.items():
                 if arch in _arches(verinfo):
@@ -660,7 +660,7 @@ class AutoPackageTest(object):
         pkg_arch_result = {}
         trigger = trigsrc + '/' + trigver
 
-        for arch in self.britney.options.adt_arches.split():
+        for arch in self.britney.options.adt_arches:
             for testsrc, testver in self.tests_for_source(trigsrc, trigver, arch):
                 try:
                     (_, ver_map, ever_passed) = self.test_results[testsrc][arch]

britney.py

@@ -460,6 +460,7 @@ class Britney(object):
         self.options.outofsync_arches = self.options.outofsync_arches.split()
         self.options.break_arches = self.options.break_arches.split()
         self.options.new_arches = self.options.new_arches.split()
+        self.options.adt_arches = self.options.adt_arches.split()
 
         # Sort the architecture list
         allarches = sorted(self.options.architectures.split())
@@ -1592,7 +1593,7 @@ class Britney(object):
                     text = text + " (but %s isn't keeping up, so never mind)" % (arch)
                 else:
                     update_candidate = False
-                    if arch in self.options.adt_arches.split():
+                    if arch in self.options.adt_arches:
                         run_autopkgtest = False
                     if arch in self.options.boottest_arches.split():
                         run_boottest = False
@@ -1636,7 +1637,7 @@ class Britney(object):
                 if binary_u[ARCHITECTURE] != 'all' or arch in self.options.nobreakall_arches:
                     if not self.excuse_unsat_deps(pkg, src, arch, suite, excuse):
                         update_candidate = False
-                        if arch in self.options.adt_arches.split():
+                        if arch in self.options.adt_arches:
                             run_autopkgtest = False
                         if arch in self.options.boottest_arches.split():
                             run_boottest = False
@@ -1664,7 +1665,7 @@ class Britney(object):
                     text = text + " (but %s isn't keeping up, so nevermind)" % (arch)
                 else:
                     update_candidate = False
-                    if arch in self.options.adt_arches.split():
+                    if arch in self.options.adt_arches:
                         run_autopkgtest = False
                     if arch in self.options.boottest_arches.split():
                         run_boottest = False