power: supply: ab8500: Remove unused variable

Kernel test robot reported below warning ->
drivers/power/supply/ab8500_chargalg.c:790:13: warning:
variable 'delta_i_ua' set but not used [-Wunused-but-set-variable]

Remove unused variable delta_i_ua.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/ab8500_chargalg.c

@@ -800,13 +800,10 @@ static void init_maxim_chg_curr(struct ab8500_chargalg *di)
  */
 static enum maxim_ret ab8500_chargalg_chg_curr_maxim(struct ab8500_chargalg *di)
 {
-	int delta_i_ua;
 
 	if (!di->bm->maxi->ena_maxi)
 		return MAXIM_RET_NOACTION;
 
-	delta_i_ua = di->ccm.original_iset_ua - di->batt_data.inst_curr_ua;
-
 	if (di->events.vbus_collapsed) {
 		dev_dbg(di->dev, "Charger voltage has collapsed %d\n",
 				di->ccm.wait_cnt);