[Fix] - fpgasupdate -- skip Factory check under certain conditions

[anandhv]

Description

A check was recently added to fpgasupdate to prevent writing to the flash factory page when the current boot-page is also factory. This combo is in fact already prevented in the hardware by the BMC but a vague error message is propagated back to the SW stack. So the purpose of the check in fpgasupdate is to enable printing of a descriptive message to the user.

This check works for n6001 and beyond, and PACSigned binaries, but was shown to fail on D5005 systems and with .gbs files.

The D5005 failure seems to be because the boot-page sysfs entry is missing on such installations.
The .gbs failure is because such binaries are missing the Auth Block0 segment.

This change simply skips the check if either of the above conditions is true. It is OK to skip this because the BMC prevents the combo anyways.

Tests run:

• Tested on Comet Creek to ensure the check errors-out, as expected, for factory images.
• Tested on D5005 to ensure programming now completes successfully.
• Tested on N6001 to ensure programming a .gbs files completes successfully.

[pcolberg]

Thanks @anandhv for the clear commit message! I could fully understand the issue despite having no previous exposure and without having to consult the code.