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/app/wwctl/overlay/list/main.go

@@ -38,7 +38,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		if util.IsDir(path) {
 			files := util.FindFiles(path)
 
-			wwlog.Debug("Iterating overlay path: %s\n", path)
+			wwlog.Debug("Iterating overlay path: %s", path)
 			if ListContents {
 				var fileCount int
 				for file := range files {
@@ -68,7 +68,7 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 			}
 
 		} else {
-			wwlog.Error("system/%s (path not found:%s)\n", overlays[o], path)
+			wwlog.Error("system/%s (path not found:%s)", overlays[o], path)
 		}
 	}