fallback: handle buffer allocations for fh->GetInfo() prettier.
fallback: handle buffer allocations for fh->GetInfo() prettier.

At all the places we use fh->GetInfo, covscan can't tell that
fh->GetInfo() will return EFI_BUFFER_TOO_SMALL and we'll allocate on the
first try.

If we just explicitly check for "buffer == NULL" as well, covscan
believes we're doing work we don't need to (which is true!)

So instead, put an rc test to return error for everything else there, so
the allocation isn't in a conditional.

Yet another stupid one, but it's easier to nerf it this way than write
the false-positive rule, and it also hardens against incorrect UEFI
implementations (though we've not seen any yet with the problem this
avoids).

Signed-off-by: Peter Jones <2e0a021e603479ff81838c00c3b770daca4e0214@redhat.com>

rhinstaller/shim,rhinstaller/shim,rhinstaller/shim