captureffdc method returns exception object and also throws exception object

[devenrao]

It does not look correct the method captureFFDC throws an sbe_error_t exception object and the method also throws multiple sbe_error_t exceptions this does not look standard or normal.

Probably the owner choose this mechanism as captureFFDC creates an temporary FFDC file and passes the FD which I guess he could not achieve by using exceptions.
https://github.com/open-power/ipl/blob/main/libphal/phal_sbe.C#L221