tests: ls: don't always skip a capability test

* tests/ls/no-cap.sh: Move to being a root only test, since
commit v9.5-132-g2a6bed933 we now need to call setcap
to make the test effective.  Otherwise we would have always
just skipped the test.

tests/ls/no-cap.sh

@@ -19,13 +19,17 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ ls
 require_strace_ capget
+require_root_
+
+touch file || framework_failure_
+
+setcap 'cap_net_bind_service=ep' file ||
+  skip_ "setcap doesn't work"
 
 LS_COLORS=ca=1; export LS_COLORS
 strace -e capget ls --color=always > /dev/null 2> out || fail=1
 $EGREP 'capget\(' out || skip_ "your ls doesn't call capget"
 
-rm -f out
-
 LS_COLORS=ca=:; export LS_COLORS
 strace -e capget ls --color=always > /dev/null 2> out || fail=1
 $EGREP 'capget\(' out && fail=1