Fix boot_path Path loading

the boot path is a charlist eg erlang "".

But storing it in nvs with nvs_put_binary, means it's stored as a binary.

minimal fix.

Signed-off-by: Peter M <petermm@gmail.com>

libs/esp32boot/esp32init.erl

@@ -85,7 +85,7 @@ get_boot_path() ->
         undefined ->
             "/dev/partition/by-name/main.avm";
         Path ->
-            Path
+            binary_to_list(Path)
     end.
 
 get_start_module() ->