xfstests: remove fio config files after finished test

After finished test, temporarily fio config file should be removed.
This commit tries to fix this problem in the following test cases:
  - generic/299-300
  - ext4/301-304
  - shared/305

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>

tests/ext4/303

@@ -29,6 +29,7 @@ echo "QA output created by $seq"
 
 here=`pwd`
 tmp=/tmp/$$
+fio_config=$tmp.fio
 status=1	# failure is the default!
 trap "rm -f $tmp.*; exit \$status" 0 1 2 3 15
 
@@ -49,7 +50,7 @@ BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
 # Reserve space for 4 files in order to avoid ENOSPC
 FILE_SIZE=$((BLK_DEV_SIZE * (512 / (3+1))))
 
-cat >$tmp-$seq.fio <<EOF
+cat >$fio_config <<EOF
 # Common e4defrag regression tests
 [global]
 ioengine=ioe_e4defrag
@@ -127,11 +128,11 @@ _workout()
 	echo ""
 	echo " Start defragment activity"
 	echo ""
-	cat $tmp-$seq.fio >>  $seqres.full
-	run_check $FIO_PROG $tmp-$seq.fio
+	cat $fio_config >>  $seqres.full
+	run_check $FIO_PROG $fio_config
 }
 
-_require_fio $tmp-$seq.fio
+_require_fio $fio_config
 
 _scratch_mkfs  >> $seqres.full 2>&1
 _scratch_mount