file_sys/errors: Remove currently unused filesystem error codes

Rather than keeping around unused values, we can just introduce them as
needed.

src/core/file_sys/errors.h

@@ -8,16 +8,6 @@
 
 namespace FileSys {
 
-// TODO(bunnei): Replace these with correct errors for Switch OS
-constexpr ResultCode ERROR_INVALID_PATH(-1);
-constexpr ResultCode ERROR_UNSUPPORTED_OPEN_FLAGS(-1);
-constexpr ResultCode ERROR_INVALID_OPEN_FLAGS(-1);
-constexpr ResultCode ERROR_FILE_NOT_FOUND(-1);
-constexpr ResultCode ERROR_UNEXPECTED_FILE_OR_DIRECTORY(-1);
-constexpr ResultCode ERROR_DIRECTORY_ALREADY_EXISTS(-1);
-constexpr ResultCode ERROR_FILE_ALREADY_EXISTS(-1);
-constexpr ResultCode ERROR_DIRECTORY_NOT_EMPTY(-1);
-
 constexpr ResultCode ERROR_PATH_NOT_FOUND{ErrorModule::FS, 1};
 constexpr ResultCode ERROR_ENTITY_NOT_FOUND{ErrorModule::FS, 1002};
 constexpr ResultCode ERROR_SD_CARD_NOT_FOUND{ErrorModule::FS, 2001};