Revert "flounder: fixed UMP capability receive stub to properly call receive handler under all circumstances."
Revert "flounder: fixed UMP capability receive stub to properly call receive handler under all circumstances."

As it turns out this wasn't a bug at all, I just didn't understand how UMP
transfers multiple caps.

This reverts commit
git: 65b4f2e4e08ed0b126eb8be03ac5bea8a63dc1b6
hg:  f633ef1624182427285b9445d40e0c485fd51ffa

BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,utsav2601/cmpe295A,BarrelfishOS/barrelfish,kishoredbn/barrelfish,linusyang/barrelfish,mslovy/barrelfish,kishoredbn/barrelfish,utsav2601/cmpe295A,kishoredbn/barrelfish,8l/barrelfish,mslovy/barrelfish,BarrelfishOS/barrelfish,mslovy/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,linusyang/barrelfish,mslovy/barrelfish,8l/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,8l/barrelfish,8l/barrelfish,linusyang/barrelfish,BarrelfishOS/barrelfish,linusyang/barrelfish,linusyang/barrelfish,kishoredbn/barrelfish,mslovy/barrelfish,mslovy/barrelfish,utsav2601/cmpe295A,utsav2601/cmpe295A,8l/barrelfish,8l/barrelfish,utsav2601/cmpe295A,utsav2601/cmpe295A,BarrelfishOS/barrelfish