drm/amdgpu: Avoid printing of stack contents on firmware load error

In case when psp_init_asd_microcode() fails to load ASD microcode file,
psp_v12_0_init_microcode() tries to print the firmware filename that
failed to load before bailing out.

This is wrong because:

- the firmware filename it would want it print is an incorrect one as
  psp_init_asd_microcode() and psp_v12_0_init_microcode() are loading
  different filenames
- it tries to print fw_name, but that's not yet been initialized by that
  time, so it prints random stack contents, e.g.

    amdgpu 0000:04:00.0: Direct firmware load for amdgpu/renoir_asd.bin failed with error -2
    amdgpu 0000:04:00.0: amdgpu: fail to initialize asd microcode
    amdgpu 0000:04:00.0: amdgpu: psp v12.0: Failed to load firmware "\xfeTO\x8e\xff\xff"

Fix that by bailing out immediately, instead of priting the bogus error
message.

Reported-by: Vojtech Pavlik <vojtech@ucw.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org