hterm: fix DECSET/DECRST 1048 handling
hterm: fix DECSET/DECRST 1048 handling

This code path was treating DECRST 1048 as DECSET 1048, and both
were incorrectly falling through to the 1049 code path.

Change-Id: If36eb8d350eaadb8d2c9227b0ca98c64ac208747
Reviewed-on: https://chromium-review.googlesource.com/764683
Reviewed-by: Brandon Gilmore <adbfbaf7e4f927b45ce8ad3e5043a632414a833b@google.com>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>

chromium/hterm,chromium/hterm,chromium/hterm,chromium/hterm