Add { } to variables

 On branch feature/gefs_v13_822_add_atm_fcst
 Changes to be committed:
	modified:   scripts/exgdas_enkf_fcst.sh
	modified:   ush/forecast_predet.sh

Refs: NOAA-EMC#822

scripts/exgdas_enkf_fcst.sh

@@ -108,7 +108,7 @@ export LEVS=${LEVS_ENKF:-${LEVS:-64}}
 
 # nggps_diag_nml
 export FHOUT=${FHOUT_ENKF:-3}
-if [[ $CDUMP == "gfs" ]]; then
+if [[ ${CDUMP} == "gfs" ]]; then
     export FHOUT=${FHOUT_ENKF_GFS:-${FHOUT_ENKF:${FHOUT:-3}}}
 fi
 # model_configure

ush/forecast_predet.sh

@@ -208,7 +208,7 @@ FV3_GFS_predet(){
   print_freq=${print_freq:-6}
 
   #-------------------------------------------------------
-  if [[ $CDUMP = "gfs" || $RUN = "gefs" ]] && [ $rst_invt1 -gt 0 ]; then
+  if [[ ${CDUMP} = "gfs" || ${RUN} = "gefs" ]] && [ ${rst_invt1} -gt 0 ]; then
     RSTDIR_ATM=${RSTDIR_ATM:-${RSTDIR:-$ROTDIR}/${CDUMP}.${PDY}/${cyc}/atmos/RERUN_RESTART}
     if [ ! -d $RSTDIR_ATM ]; then mkdir -p $RSTDIR_ATM ; fi
     $NLN $RSTDIR_ATM RESTART
@@ -232,7 +232,7 @@ FV3_GFS_predet(){
 
   #-------------------------------------------------------
   # member directory
-  if [[ $MEMBER -lt 0 || $RUN = "gefs" ]]; then
+  if [[ ${MEMBER} -lt 0 || ${RUN} = "gefs" ]]; then
     prefix=$CDUMP
     rprefix=$rCDUMP
     memchar=""
@@ -241,13 +241,13 @@ FV3_GFS_predet(){
     rprefix=enkf$rCDUMP
     memchar=mem$(printf %03i $MEMBER)
   fi
-  memdir=${memdir:-$ROTDIR/${prefix}.$PDY/$cyc/$memchar/atmos}
+  memdir=${memdir:-${ROTDIR}/${prefix}.${PDY}/${cyc}/${memchar}/atmos}
   if [ ! -d $memdir ]; then mkdir -p $memdir; fi
 
   GDATE=$($NDATE -$assim_freq $CDATE)
   gPDY=$(echo $GDATE | cut -c1-8)
   gcyc=$(echo $GDATE | cut -c9-10)
-  gmemdir=${gmemdir:-$ROTDIR/${rprefix}.$gPDY/$gcyc/$memchar/atmos}
+  gmemdir=${gmemdir:-${ROTDIR}/${rprefix}.${gPDY}/${gcyc}/${memchar}/atmos}
 
   if [[ "$DOIAU" = "YES" ]]; then
     sCDATE=$($NDATE -3 $CDATE)