efi_loader: Use puts() in cout so that console recording works

At present EFI output to the console uses fputs() which bypasses the
console-recording feature. This makes it impossible for tests to check
the output of an EFI app.

There doesn't seem to be any need to do this bypass, so adjust it to
simply use the puts() function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>