torture: Stop overwriting Make.out file with obsolete version

The old approach placed all the build products into the b* directories,
which meant that some of these build products needed to be copied to
the proper directory in the res hierarchy.  The new approach leaves
things like .config and the .o files in the b1 directory, but directs
build output and diagnostics directly to the proper directory in the
res hierarchy.  Unfortunately, one of the copies was still carried out,
which could (and sometimes did) overwrite the build output and diagnostics
with obsolete output remaining in the b1 directory.

This commit therefore removes the offending "cp" command.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>