runtime: Ignore empty throttlers in collect script

Fix bug by ignoring empty throttlers in the data collection script.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

src/runtime/data/kata-collect-data.sh.in

@@ -658,6 +658,8 @@ show_throttler_details()
 
 	echo "$throttlers" | while read throttler
 	do
+		[ -z "$throttler" ] && continue
+
 		local cmd
 		cmd="$throttler --version"
 		run_cmd_and_show_quoted_output "" "$cmd"