There is a extra call to igt_pipe_crc_start that is not matched to any
stop. Because of this the exit handler tries to reset the crc source on
exit while the pipe disabled. This causes fails with -EIO:

(kms_chv_cursor_fail:2643) igt-debugfs-CRITICAL: Test assertion failure
function igt_pipe_crc_pipe_off, file igt_debugfs.c:364:
(kms_chv_cursor_fail:2643) igt-debugfs-CRITICAL: Failed assertion:
write(fd, buf, strlen(buf)) == strlen(buf)
(kms_chv_cursor_fail:2643) igt-debugfs-CRITICAL: Last errno: 5, EIO
(kms_chv_cursor_fail:2643) igt-debugfs-CRITICAL: error: -1 != 11
Stack trace:
  #0 [__igt_fail_assert+0xf1]
  #1 [igt_pipe_crc_pipe_off+0xe4]
  #2 [pipe_crc_exit_handler+0x35]
  #3 [igt_atexit_handler+0x4c]
  #4 [__libc_secure_getenv+0x112]
  #5 [exit+0x15]
  #6 [igt_exit+0xd6]
  #7 [main+0x1ee]
  #8 [__libc_start_main+0xf0]
  #9 [_start+0x29]
  #10

 [<unknown>+0x29]

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>