seat/pointer: fix uninitialized variable warning

This results in the following warning, which in release mode causes an
error due to -Werror:

../types/seat/wlr_seat_pointer.c: In function ‘wlr_seat_pointer_send_axis’:
../types/seat/wlr_seat_pointer.c:344:25: error: ‘low_res_value_discrete’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  343 |   if (version < WL_POINTER_AXIS_VALUE120_SINCE_VERSION &&
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  344 |     value_discrete != 0 && low_res_value_discrete == 0) {
      |     ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

0 files changed, 0 insertions, 0 deletions