fwupdate: Add error checking for invalid tar.gz packages
fwupdate: Add error checking for invalid tar.gz packages

Also, only send MC reset to successful targets.

Cynerva/cxmanage,SLS-Dev/cxmanage,SilverLiningSystems/cxmanage-test,SilverLiningSystems/cxmanage-test,SilverLiningSystems/cxmanage-test2,SLS-Dev/cxmanage,Cynerva/cxmanage,SilverLiningSystems/cxmanage-test2