Remove trailing newline from wwlog

I noticed that some wwlog calls included a trailing newline, but others
did not. I tested both in isolation and discovered that the behavior was
consistent regardless of whether a trailing newline was included. I
further confirmed in code that wwlog appends a trailing newline
automatically if it is not present; so a trailing newline is unnecessary
in individual calls.

This commit removes trailing newlines from all calls to make them
consistent. It also replaces two calls to wwlog.Printf. (see #534)

Signed-off-by: Jonathon Anderson <janderson@ciq.co>

internal/pkg/overlay/datastructure.go

@@ -44,17 +44,17 @@ func InitStruct(nodeInfo node.NodeInfo) TemplateStruct {
 	var tstruct TemplateStruct
 	controller, err := warewulfconf.New()
 	if err != nil {
-		wwlog.Error("%s\n", err)
+		wwlog.Error("%s", err)
 		os.Exit(1)
 	}
 	nodeDB, err := node.New()
 	if err != nil {
-		wwlog.Error("%s\n", err)
+		wwlog.Error("%s", err)
 		os.Exit(1)
 	}
 	allNodes, err := nodeDB.FindAllNodes()
 	if err != nil {
-		wwlog.Error("%s\n", err)
+		wwlog.Error("%s", err)
 		os.Exit(1)
 	}
 	// init some convininence vars