wifi: ath9k: Remove unused variable mismatch

Variable mismatch is just being incremented and it's never used anywhere
else. The variable and the increment are redundant so remove it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20221104140723.226857-1-colin.i.king@gmail.com

drivers/net/wireless/ath/ath9k/ar9003_mci.c

@@ -585,7 +585,7 @@ static u32 ar9003_mci_wait_for_gpm(struct ath_hw *ah, u8 gpm_type,
 {
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath9k_hw_mci *mci = &ah->btcoex_hw.mci;
-	u32 *p_gpm = NULL, mismatch = 0, more_data;
+	u32 *p_gpm = NULL, more_data;
 	u32 offset;
 	u8 recv_type = 0, recv_opcode = 0;
 	bool b_is_bt_cal_done = (gpm_type == MCI_GPM_BT_CAL_DONE);
@@ -656,7 +656,6 @@ static u32 ar9003_mci_wait_for_gpm(struct ath_hw *ah, u8 gpm_type,
 		} else {
 			ath_dbg(common, MCI, "MCI GPM subtype not match 0x%x\n",
 				*(p_gpm + 1));
-			mismatch++;
 			ar9003_mci_process_gpm_extra(ah, recv_type,
 						     recv_opcode, p_gpm);
 		}