PRD: remove empty TD controller data

Change-Id: I088b81ee9be0945e04370f2d094c9569d51fc5d2
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/60004
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Benjamin J. Weisenbeck <bweisenb@us.ibm.com>
Reviewed-by: Matt Derksen <mderkse1@us.ibm.com>
Reviewed-by: Caleb N. Palmer <cnpalmer@us.ibm.com>
Reviewed-by: Brian J. Stegmiller <bjs@us.ibm.com>
Reviewed-by: Zane C. Shelley <zshelle@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/60146
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>

src/usr/diag/prdf/plat/mem/prdfMemTdCtlr.C

@@ -397,6 +397,9 @@ void MemTdCtlr<T>::collectStateCaptureData( STEP_CODE_DATA_STRUCT & io_sc,
     uint8_t queueCount = queue.size();
     if ( 15 < queueCount ) queueCount = 15;
 
+    // Don't add anything if there is no data.
+    if ( nullptr == iv_curProcedure && 0 == queueCount ) return;
+
     // Get the buffer
     uint32_t bitLen = 32 + queueCount*14; // Header + TD queue
     BitStringBuffer bsb( bitLen );