[Code formatting: Change indentation style to space](https://github.com/clicon/clixon/issues/379)

* Applies to all c/h/y/l/sh files and .editorconfig

test/test_perf_state.sh

@@ -102,7 +102,7 @@ if [ $BE -ne 0 ]; then
     new "kill old backend"
     sudo clixon_backend -zf $cfg
     if [ $? -ne 0 ]; then
-	err
+        err
     fi
 
     new "start backend -s init -f $cfg -- -sS $fstate"
@@ -211,7 +211,7 @@ if [ $BE -ne 0 ]; then
     # Check if premature kill
     pid=$(pgrep -u root -f clixon_backend)
     if [ -z "$pid" ]; then
-	err "backend already dead"
+        err "backend already dead"
     fi
     # kill backend
     stop_backend -f $cfg