Fix '-f' option to force full backup

Related: PROD-32205

Change-Id: If3fb18df60748735c4e2f3f18d4d2a4714360f0a
diff --git a/xtrabackup/files/innobackupex-client-runner.sh b/xtrabackup/files/innobackupex-client-runner.sh
index 2da7a53..f17238f 100644
--- a/xtrabackup/files/innobackupex-client-runner.sh
+++ b/xtrabackup/files/innobackupex-client-runner.sh
@@ -133,9 +133,9 @@
     compression_threads=
   fi
 
-  if [ "$BACKUPTIME"==false ]; then
+  if [ "$BACKUPTIME" != true ]; then
     # Run an incremental backup if latest full is still valid. Otherwise, run a new full one.
-    if [ "$LATEST_FULL" -a $(expr $LATEST_FULL_CREATED_AT + $FULLBACKUPLIFE + 5) -ge $STARTED_AT ] ; then
+    if [ "$LATEST_FULL" -a $(expr $LATEST_FULL_CREATED_AT + $FULLBACKUPLIFE + 5) -ge $STARTED_AT ] && [ "$FORCEFULL" != true ] ; then
       # Create incremental backups dir if not exists.
       TMPINCRDIR="$INCRBACKUPDIR/$LATEST_FULL"
       mkdir -p $TMPINCRDIR
@@ -164,7 +164,7 @@
     echo "Number of Incremental backups stored: " $NUMBER_OF_INCR
     echo "----------------------------"
     #If number of incremental mod number of full backups to keep equals 1, run full backup, otherwise run incremental
-    if [ $(( ($NUMBER_OF_INCR + $NUMBER_OF_FULL) % ($INCRBEFOREFULL + 1) )) -eq 0 ] || [ FORCEFULL=true ] ; then
+    if [ $(( ($NUMBER_OF_INCR + $NUMBER_OF_FULL) % ($INCRBEFOREFULL + 1) )) -eq 0 ] || [ "$FORCEFULL" == true ] ; then
       echo "Running new full backup."
       innobackupex --defaults-file=$MYCNF $USEROPTIONS $compress $compression_threads $FULLBACKUPDIR 2>&1 | tee $TMPFILE
     else
@@ -219,8 +219,8 @@
 function cleanup_backup()
 {
   # Cleanup
-  if [ "$SKIPCLEANUP"==false ] ; then
-    if [ "$BACKUPTIME"==false ]; then
+  if [ "$SKIPCLEANUP" == false ] ; then
+    if [ "$BACKUPTIME" != true ]; then
       echo "----------------------------"
       echo "Cleanup. Keeping only $KEEP full backups and its incrementals."
       AGE=$(($FULLBACKUPLIFE * $KEEP / 60))
@@ -247,7 +247,7 @@
     fi
   else
     echo "----------------------------"
-    echo "--skip-cleanup parameter passed. Cleanup was not triggered"
+    echo "-s parameter passed. Cleanup was not triggered"
   fi
 }