form David Rohr: Fix crash during QA part of rec.C
form David Rohr: Fix crash during QA part of rec.C

AliHLTQADataMakerRec.cxx:
previously set gDirectory to 0 temporarily, in order to prevent
histograms beeing added to current directory. With new root,
this causes a crash during TObject::clone. Hence we use the
propper way to disable histograms beeing added to gDirectory
temporarily, and reset it afterwards

jgrosseo/AliRoot,sebaleh/AliRoot,jgrosseo/AliRoot,ecalvovi/AliRoot,alisw/AliRoot,ecalvovi/AliRoot,coppedis/AliRoot,coppedis/AliRoot,shahor02/AliRoot,sebaleh/AliRoot,mkrzewic/AliRoot,coppedis/AliRoot,shahor02/AliRoot,alisw/AliRoot,miranov25/AliRoot,miranov25/AliRoot,mkrzewic/AliRoot,jgrosseo/AliRoot,ALICEHLT/AliRoot,alisw/AliRoot,miranov25/AliRoot,miranov25/AliRoot,alisw/AliRoot,ALICEHLT/AliRoot,ALICEHLT/AliRoot,miranov25/AliRoot,sebaleh/AliRoot,mkrzewic/AliRoot,coppedis/AliRoot,alisw/AliRoot,coppedis/AliRoot,jgrosseo/AliRoot,miranov25/AliRoot,alisw/AliRoot,sebaleh/AliRoot,ecalvovi/AliRoot,ALICEHLT/AliRoot,shahor02/AliRoot,sebaleh/AliRoot,ecalvovi/AliRoot,jgrosseo/AliRoot,coppedis/AliRoot,shahor02/AliRoot,coppedis/AliRoot,mkrzewic/AliRoot,mkrzewic/AliRoot,shahor02/AliRoot,ALICEHLT/AliRoot,ecalvovi/AliRoot,jgrosseo/AliRoot,ALICEHLT/AliRoot,miranov25/AliRoot,shahor02/AliRoot,mkrzewic/AliRoot,ecalvovi/AliRoot,alisw/AliRoot,mkrzewic/AliRoot,sebaleh/AliRoot,shahor02/AliRoot,alisw/AliRoot,ecalvovi/AliRoot,ALICEHLT/AliRoot,coppedis/AliRoot,jgrosseo/AliRoot,miranov25/AliRoot,sebaleh/AliRoot