Input: avoid calling input_set_abs_val() in the event handling core

Input: avoid calling input_set_abs_val() in the event handling core

input_abs_set_val() can nominally call input_alloc_absinfo() which may
allocate memory with GFP_KERNEL flag. This does not happen when
input_abs_set_val() is called by the input core to set current MT slot when
handling a new input event, but it trips certain static analyzers.

Rearrange the code to access the relevant structures directly.

Reported-by: Teng Qi <starmiku1207184332@gmail.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://lore.kernel.org/r/ZFBg379uuHjf+YEM@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>