ext4/002: Fix obsolete TEST_DEV/TEST_DIR in _check_ext4_eof_flag()

Commit 6b06a9bb6f has used SCRATCH_DEV/SCRATCH_MNT rather than
TEST_DEV/TEST_DIR for holding the test files, so we need to use
SCRATCH_DEV/SCRATCH_MNT in _check_ext4_eof_flag() as well.

Fixes: 6b06a9bb6f ("ext4/002: Work with 64k block size")
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

tests/ext4/002

@@ -62,11 +62,11 @@ _check_ext4_eof_flag()
   if [ "${FSTYP}" == "ext4" ]; then
     bit_set=1
 
-    # Unmount the ${TEST_DEV}
-    _test_unmount
+    # Unmount the ${SCRATCH_DEV}
+    _scratch_unmount
 
     # Run debugfs to gather file_parameters - specifically iflags.
-    file_params=`debugfs ${TEST_DEV} -R "stat ${1}" 2>&1 | grep -e Flags:`
+    file_params=`debugfs ${SCRATCH_DEV} -R "stat ${1}" 2>&1 | grep -e Flags:`
     iflags=${file_params#*Flags: }
 
     # Ensure that the iflags value was parsed correctly.
@@ -92,8 +92,8 @@ _check_ext4_eof_flag()
       exit ${status}
     fi
 
-    # Mount the ${TEST_DEV}
-    mount ${TEST_DEV} -t ${FSTYP} ${TEST_DIR}
+    # Mount the ${SCRATCH_DEV}
+    _scratch_mount
   fi
 }