agent.sh: Replaced "&>>" redirection by ">> 2>&1"

Replaced to avoid error in old bash(1) versions, since this is somewhat a
new kind of redirection.

Signed-off-by: Erik Alexandre Pucci <eap08@c3sl.ufpr.br>
Signed-off-by: Victor Tarabola Cortiano <vtc10@c3sl.ufpr.br>

agent.sh

@@ -115,7 +115,7 @@ export PREFIX="$(dirname $(readlink -f $0))"
 source ${PREFIX}/load-config.sh || exit 6
 source ${PREFIX}/client/common.sh
 
-exec &>> ${LOGFILE}
+exec >> ${LOGFILE} 2>&1
 
 # Run extra scripts before anything
 for script in ${PREFIX}/extra/scripts/* ; do