make -C /builds/linux/tools/testing/selftests/../../../tools/arch/arm64/tools/ OUTPUT=/builds/linux/tools/testing/selftests/../../../tools/
make[4]: Entering directory '/builds/linux/tools/testing/selftests/ublk'
kublk.c: In function 'ublk_ctrl_stop_dev':
kublk.c:104:27: error: 'UBLK_U_CMD_STOP_DEV' undeclared (first use in this function); did you mean 'UBLK_CMD_STOP_DEV'?
  104 |                 .cmd_op = UBLK_U_CMD_STOP_DEV,
      |                           ^~~~~~~~~~~~~~~~~~~
      |                           UBLK_CMD_STOP_DEV
kublk.c:104:27: note: each undeclared identifier is reported only once for each function it appears in