[PATCH xfstests] generic/192: Move 'cd /' to the place where the program exits

[Zhihao Cheng <chengzhihao1@huawei.com>]

Running generic/192 with overlayfs(Let ubifs as base fs) yields the
following output:

  generic/192 - output mismatch
     QA output created by 192
     sleep for 5 seconds
     test
    +./common/rc: line 316: src/t_dir_type: No such file or directory
     delta1 is in range
     delta2 is in range
    ...

When the use case fails, the call stack in generic/192 is:

  local unknowns=$(src/t_dir_type $dir u | wc -l)	common/rc:316
  _supports_filetype					common/rc:299
  _overlay_mount					common/overlay:52
  _overlay_test_mount					common/overlay:93
  _test_mount						common/rc:407
  _test_cycle_mount					generic/192:50

Before _test_cycle_mount() being invoked, generic/192 executed 'cd /'
to change work dir from 'xfstests-dev' to '/', so src/t_dir_type was not
found.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
---
 tests/generic/192 | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tests/generic/192 b/tests/generic/192
index 50b3d6fd..5550f39e 100755
--- a/tests/generic/192
+++ b/tests/generic/192
@@ -15,7 +15,12 @@ echo "QA output created by $seq"
 here=`pwd`
 tmp=/tmp/$$
 status=1	# failure is the default!
-trap "exit \$status" 0 1 2 3 15
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+}
 
 _access_time()
 {
@@ -46,7 +51,6 @@ sleep $delay # sleep to allow time to move on for access
 cat $testfile
 time2=`_access_time $testfile | tee -a $seqres.full`
 
-cd /
 _test_cycle_mount
 time3=`_access_time $testfile | tee -a $seqres.full`
 
-- 
2.13.6