repoman: fix random package.use.stable.* failure

It failed to work randomly, since setcpv did not always use the correct
value for the effective ACCEPT_KEYWORDS of the current profile.
diff --git a/bin/repoman b/bin/repoman
index c55fb04..b948631 100755
--- a/bin/repoman
+++ b/bin/repoman
@@ -2265,8 +2265,7 @@
 				trees[root]["porttree"].settings = dep_settings
 				portdb.settings = dep_settings
 				portdb.xcache = xcache
-				# for package.use.mask support inside dep_check
-				dep_settings.setcpv(pkg)
+
 				dep_settings["ACCEPT_KEYWORDS"] = " ".join(groups)
 				# just in case, prevent config.reset() from nuking these.
 				dep_settings.backup_changes("ACCEPT_KEYWORDS")
@@ -2279,6 +2278,13 @@
 				# dependencies may conflict (see bug #456342).
 				dep_settings._parent_stable = dep_settings._isStable(pkg)
 
+				# Handle package.use*.{force,mask) calculation, for use
+				# in dep_check.
+				dep_settings.useforce = dep_settings._use_manager.getUseForce(
+					pkg, stable=dep_settings._parent_stable)
+				dep_settings.usemask = dep_settings._use_manager.getUseMask(
+					pkg, stable=dep_settings._parent_stable)
+
 				if not baddepsyntax:
 					ismasked = not ebuild_archs or \
 						pkg.cpv not in portdb.xmatch("match-visible", pkg.cp)