Remove response checking for PrepareForUpdate API post request
Remove response checking for PrepareForUpdate API post request

PrepareForUpdate would trigger immediate reboot BMC which
shuts down services.

Change-Id: I1091f558ae1d17c4379aa6e86b5912b10d948897
Signed-off-by: George Keishing <bef0a9ecac45fb57611777c8270153994e13fd2e@in.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation