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/configure/nfs.go

@@ -19,7 +19,7 @@ func NFS() error {
 
 	controller, err := warewulfconf.New()
 	if err != nil {
-		wwlog.Error("%s\n", err)
+		wwlog.Error("%s", err)
 		os.Exit(1)
 	}
 
@@ -30,7 +30,7 @@ func NFS() error {
 		if controller.Warewulf.EnableHostOverlay {
 			err = overlay.BuildHostOverlay()
 			if err != nil {
-				wwlog.Warn("host overlay could not be built: %s\n", err)
+				wwlog.Warn("host overlay could not be built: %s", err)
 			}
 		} else {
 			wwlog.Info("host overlays are disabled, did not modify exports")