soc: qcom: rpmh-rsc: tcs_is_free() can just check tcs_in_use

tcs_is_free() had two checks in it: does the software think that the
TCS is free and does the hardware think that the TCS is free.  I
couldn't figure out in which case the hardware could think that a TCS
was in-use but software thought it was free.  Apparently there is no
case and the extra check can be removed.  This apparently has already
been done in a downstream patch.
Suggested-by: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Maulik Shah <mkshah@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Maulik Shah <mkshah@codeaurora.org>
Link: https://lore.kernel.org/r/20200413100321.v4.7.Icf2213131ea652087f100129359052c83601f8b0@changeidSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/soc/qcom/rpmh-rsc.c

@@ -177,7 +177,6 @@ static void write_tcs_reg_sync(struct rsc_drv *drv, int reg, int tcs_id,
  * @tcs_id: The global ID of this TCS.
  *
  * Returns true if nobody has claimed this TCS (by setting tcs_in_use).
- * If the TCS looks free, checks that the hardware agrees.
  *
  * Context: Must be called with the drv->lock held or the tcs_lock for the TCS
  *          being tested. If only the tcs_lock is held then it is possible that
@@ -189,8 +188,7 @@ static void write_tcs_reg_sync(struct rsc_drv *drv, int reg, int tcs_id,
  */
 static bool tcs_is_free(struct rsc_drv *drv, int tcs_id)
 {
-	return !test_bit(tcs_id, drv->tcs_in_use) &&
-	       read_tcs_reg(drv, RSC_DRV_STATUS, tcs_id);
+	return !test_bit(tcs_id, drv->tcs_in_use);
 }
 
 /**