btrfs-progs: tests: add support check to convert-tests/022

[BUG]
The test case convert/022 will fail if the system doesn't have
reiserfs support nor reiserfs user space tools:

  # make TEST=022\* test-convert
    [TEST]   convert-tests.sh
  WARNING: reiserfs filesystem not listed in /proc/filesystems, some tests might be skipped
    [TEST/conv]   022-reiserfs-parent-ref
  Failed system wide prerequisities: mkreiserfs
  test failed for case 022-reiserfs-parent-ref
  make: *** [Makefile:443: test-convert] Error 1

[CAUSE]
Unlike other test cases, convert/022 doesn't even check if we have
kernel support for it.

[FIX]
Add the proper check before doing system wide prerequisities checks.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/convert-tests/022-reiserfs-parent-ref/test.sh

@@ -2,9 +2,15 @@
 # Test that only toplevel directory self-reference is created
 
 source "$TEST_TOP/common"
+source "$TEST_TOP/common.convert"
 
 setup_root_helper
 prepare_test_dev
+
+if ! check_kernel_support_reiserfs >/dev/null; then
+	_not_run "no reiserfs support"
+fi
+
 check_global_prereq mkreiserfs
 check_prereq btrfs-convert