test: Reduce dependency on #host-sel button

Drop the mobile check in TestRoles. The same check is already done in
TestMenu.

Avoid actually opening the host switcher menu in
`TestMultiMachine.testDirectLogin`, just check that the nav menu shows
that we are logged into the expected machine.

test/verify/check-shell-multi-machine

@@ -267,9 +267,7 @@ class TestMultiMachine(testlib.MachineCase):
 
         b.wait_js_cond(f'window.location.pathname == "{root}=10.111.113.2/system"')
 
-        b.click("#hosts-sel button")
-        b.wait_in_text(f"a[href='{root}=10.111.113.2/@localhost']", "machine2")
-        b.wait_not_present("a[href='/@10.111.113.2']")
+        b.wait_in_text("#hosts-sel", "machine2")
         b.logout()
 
         # Bad host key

test/verify/check-users-roles

@@ -48,11 +48,6 @@ class TestRoles(testlib.MachineCase):
         b.enter_page("/system")
         b.switch_to_top()
         b.wait_text('#current-username', 'user')
-        b.set_layout("mobile")
-        b.click("#hosts-sel button")
-        b.wait_in_text(".view-hosts .pf-m-current", "user @")
-        b.click("#hosts-sel button")
-        b.set_layout("desktop")
 
         b.go("/users#/user")
         b.enter_page("/users")