errata/sifive: remove unreliable warn_miss_errata

errata/sifive: remove unreliable warn_miss_errata

When both the SiFive and MIPS errata are enabled then
sifive_errata_patch_func emits a wrong and misleading warning claiming
that the SiFive errata haven't been applied.  This happens because
sifive_errata_patch_func is being called twice, once for the kernel image
and once for the vdso image.  The vdso image has alternative entries
for the MIPS errata, but none for the SiFive errata.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Link: https://patch.msgid.link/mvmv7i8q8gg.fsf@suse.de
Signed-off-by: Paul Walmsley <pjw@kernel.org>