remove extraneous parens

Author: Vladimir Kotal

proc.tex

@@ -469,7 +469,7 @@
 \begin{description}
 \item[process groups] make it possible to send signals to group of processes
 at once
-\item[session] is a collection of processes created for (\emph{job control}).
+\item[session] is a collection of processes created for \emph{job control}.
 
 The processes of the session share one \emph{controlling terminal}.
 Session includes one or more process groups. Maximum one group in the session