If you were paid the entire amount then you paid the sub contractor then you needed to enter in the entire amount on your return then 1099 expense his portion.
If that sub contractor was paid by the client directly then they should have not given you a 1099 for the entire amount ... only your amount should have been on the 1099 ... this should be corrected by the client ... or you can just take care of it as you are proposing to do.
