Merge remote-tracking branch 'remotes/philmd/tags/fw_cfg-20190104-pull-request' into...

fw_cfg patches for 2019-01-04

Two fixes from Li Qiang:
- Improve error message when can't load splash file
- Fix boot bootsplash and reboot-timeout error checking

# gpg: Signature made Fri 04 Jan 2019 16:22:24 GMT
# gpg:                using RSA key E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>"
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd/tags/fw_cfg-20190104-pull-request:
  fw_cfg: Make qemu_extra_params_fw locally
  fw_cfg: Fix -boot reboot-timeout error checking
  fw_cfg: Fix -boot bootsplash error checking
  fw_cfg: Improve error message when can't load splash file

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>