efi_loader: fix iteration of FMP protocols

If one of the FMP protocols fails when calling GetImageInfo(),
populating the ESRT ends up with failure and other FMP protocols
are not added to the ESRT. We should still add all other FMP
protocols to the ESRT.

With this commit, iteration of all FMP protocols continues
even though one of the FMP protocols fails.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>