fw-updater: Remove unnecessary waits after sending commands

Since the updater is always expecting an exact amount of bytes as a response from the BSL, waiting after sending a command is not necessary

BUG=None
TEST=Test the updater and verify that no issues exist after programming

Change-Id: I4b6f3c7a5b6ac03478c146d2ff53d2786b1344e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dolos/+/5472844
Reviewed-by: Samuel Jacob <samjaco@google.com>
Reviewed-by: Udaya Kiran Ammu <udaykiran@google.com>
Tested-by: Udaya Kiran Ammu <udaykiran@google.com>
Commit-Queue: Udaya Kiran Ammu <udaykiran@google.com>
1 file changed