Add sample file for surface scan

Does a write phase and then a verify phase and verifies the written
data.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/examples/surface-scan b/examples/surface-scan
new file mode 100644
index 0000000..ae15846
--- /dev/null
+++ b/examples/surface-scan
@@ -0,0 +1,23 @@
+; writes 512 byte verification blocks until the disk is full,
+; then verifies written data
+[global]
+thread=1
+bs=4k
+direct=1
+ioengine=sync
+verify=meta
+verify_pattern=0xaa555aa5
+verify_interval=512
+
+[write-phase]
+filename=datafile.tmp	; or use a full disk, for example /dev/sda
+rw=write
+fill_device=1
+do_verify=0
+
+[verify-phase]
+stonewall
+create_serialize=0
+filename=datafile.tmp
+rw=read
+do_verify=1