i2c: riic: Use dev_err_probe in probe and riic_init_hw functions

Refactor error handling in the riic_i2c_probe() and riic_init_hw()
functions by replacing multiple dev_err() calls with dev_err_probe().

Additionally, update the riic_init_hw() function to use a local `dev`
pointer instead of `riic->adapter.dev` for dev_err_probe(), as the I2C
adapter is not initialized at this stage. Drop the cast to (unsigned long)
in the riic_init_hw() function when printing the bus frequency, and update
the error message to display the frequency in Hz, improving clarity.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Author: prabhakarlad

drivers/i2c/busses/i2c-riic.c

@@ -356,11 +356,9 @@ static int riic_init_hw(struct riic_dev *riic)
 		rate /= 2;
 	}
 
-	if (brl > (0x1F + 3)) {
-		dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
-			(unsigned long)t->bus_freq_hz);
-		return -EINVAL;
-	}
+	if (brl > (0x1F + 3))
+		return dev_err_probe(dev, -EINVAL, "invalid speed (%uHz). Too slow.\n",
+				     t->bus_freq_hz);
 
 	brh = total_ticks - brl;
 
@@ -445,10 +443,9 @@ static int riic_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(riic->base);
 
 	riic->clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(riic->clk)) {
-		dev_err(dev, "missing controller clock");
-		return PTR_ERR(riic->clk);
-	}
+	if (IS_ERR(riic->clk))
+		return dev_err_probe(dev, PTR_ERR(riic->clk),
+				     "missing controller clock");
 
 	riic->rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
 	if (IS_ERR(riic->rstc))
@@ -472,10 +469,9 @@ static int riic_i2c_probe(struct platform_device *pdev)
 
 		ret = devm_request_irq(dev, irq, riic_irqs[i].isr,
 				       0, riic_irqs[i].name, riic);
-		if (ret) {
-			dev_err(dev, "failed to request irq %s\n", riic_irqs[i].name);
-			return ret;
-		}
+		if (ret)
+			return dev_err_probe(dev, ret, "failed to request irq %s\n",
+					     riic_irqs[i].name);
 	}
 
 	riic->info = of_device_get_match_data(dev);