Do it the same way as done in microcode_intel.c: use pr_debug()
for missing firmware files.
There seem to be CPUs out there for which no microcode update
has been submitted to kernel-firmware repo yet resulting in
scary sounding error messages in dmesg:
  microcode: failed to load file amd-ucode/microcode_amd_fam16h.bin
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1384274383-43510-1-git-send-email-trenn@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
                snprintf(fw_name, sizeof(fw_name), "amd-ucode/microcode_amd_fam%.2xh.bin", c->x86);
 
        if (request_firmware(&fw, (const char *)fw_name, device)) {
-               pr_err("failed to load file %s\n", fw_name);
+               pr_debug("failed to load file %s\n", fw_name);
                goto out;
        }