fx.cmdline: fix namespace not having the required header subdirectory

fx.cmdline/test/example.c

@@ -1,4 +1,4 @@
-#include <fx/cmd.h>
+#include <fx/cmdline/cmd.h>
 #include <stdio.h>
 
 enum {
@@ -27,16 +27,24 @@ const char *text
 	  "great pleasure.";
 
 static int test_command(
-	const fx_command *self, const fx_arglist *opt, const fx_array *args)
+	const fx_command *self,
+	const fx_arglist *opt,
+	const fx_array *args)
 {
 	printf("Hello, world!\n");
 
 	fx_arglist_iterator it;
 	fx_arglist_iterator_begin(
-		opt, FX_COMMAND_INVALID_ID, FX_COMMAND_INVALID_ID, &it);
+		opt,
+		FX_COMMAND_INVALID_ID,
+		FX_COMMAND_INVALID_ID,
+		&it);
 	while (fx_arglist_iterator_is_valid(&it)) {
-		printf("opt:%u,arg:%u,i:%zu,value: %s\n", it.opt_id,
-		       it.value->val_id, it.i, it.value->val_str);
+		printf("opt:%u,arg:%u,i:%zu,value: %s\n",
+		       it.opt_id,
+		       it.value->val_id,
+		       it.i,
+		       it.value->val_str);
 
 		fx_arglist_iterator_next(&it);
 	}