Skip the test if the system doesn't contain any RPM packages

Author: jan-cerny

tests/probes/rpm/rpminfo/test_probes_rpminfo.sh

@@ -21,6 +21,7 @@ require "rpm" || exit 255
 A_NAME=`rpm --qf "%{NAME}\n" -qa | sort | uniq -u | sed -n '1p'`
 B_NAME=`rpm --qf "%{NAME}\n" -qa | sort | uniq -u | sed -n '2p'`
 
+[ -n "$A_NAME" ] || exit 255
 
 test_init