dsa: Use str_enable_disable-like helpers

Replace ternary (condition ? "enable" : "disable") syntax with helpers
from string_choices.h because:
1. Simple function call with one argument is easier to read.  Ternary
   operator has three arguments and with wrapping might lead to quite
   long code.
2. Is slightly shorter thus also easier to read.
3. It brings uniformity in the text - same string.
4. Allows deduping by the linker, which results in a smaller binary
   file.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/pcs-639x.c

@@ -9,6 +9,7 @@
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/mii.h>
+#include <linux/string_choices.h>
 
 #include "chip.h"
 #include "global2.h"
@@ -750,7 +751,7 @@ static int mv88e6393x_sgmii_apply_2500basex_an(struct mv88e639x_pcs *mpcs,
 	if (err)
 		dev_err(mpcs->mdio.dev.parent,
 			"failed to %s 2500basex fix: %pe\n",
-			enable ? "enable" : "disable", ERR_PTR(err));
+			str_enable_disable(enable), ERR_PTR(err));
 
 	return err;
 }

drivers/net/dsa/mv88e6xxx/port.c

@@ -13,6 +13,7 @@
 #include <linux/phy.h>
 #include <linux/phylink.h>
 #include <linux/property.h>
+#include <linux/string_choices.h>
 
 #include "chip.h"
 #include "global2.h"
@@ -176,7 +177,7 @@ int mv88e6xxx_port_set_link(struct mv88e6xxx_chip *chip, int port, int link)
 
 	dev_dbg(chip->dev, "p%d: %s link %s\n", port,
 		reg & MV88E6XXX_PORT_MAC_CTL_FORCE_LINK ? "Force" : "Unforce",
-		reg & MV88E6XXX_PORT_MAC_CTL_LINK_UP ? "up" : "down");
+		str_up_down(reg & MV88E6XXX_PORT_MAC_CTL_LINK_UP));
 
 	return 0;
 }

drivers/net/dsa/realtek/rtl8366rb.c

@@ -21,6 +21,7 @@
 #include <linux/irqchip/chained_irq.h>
 #include <linux/of_irq.h>
 #include <linux/regmap.h>
+#include <linux/string_choices.h>
 
 #include "realtek.h"
 #include "realtek-smi.h"
@@ -1522,7 +1523,7 @@ static int rtl8366rb_vlan_filtering(struct dsa_switch *ds, int port,
 	rb = priv->chip_data;
 
 	dev_dbg(priv->dev, "port %d: %s VLAN filtering\n", port,
-		vlan_filtering ? "enable" : "disable");
+		str_enable_disable(vlan_filtering));
 
 	/* If the port is not in the member set, the frame will be dropped */
 	ret = regmap_update_bits(priv->map, RTL8366RB_VLAN_INGRESS_CTRL2_REG,
@@ -1884,15 +1885,15 @@ static bool rtl8366rb_is_vlan_valid(struct realtek_priv *priv, unsigned int vlan
 
 static int rtl8366rb_enable_vlan(struct realtek_priv *priv, bool enable)
 {
-	dev_dbg(priv->dev, "%s VLAN\n", enable ? "enable" : "disable");
+	dev_dbg(priv->dev, "%s VLAN\n", str_enable_disable(enable));
 	return regmap_update_bits(priv->map,
 				  RTL8366RB_SGCR, RTL8366RB_SGCR_EN_VLAN,
 				  enable ? RTL8366RB_SGCR_EN_VLAN : 0);
 }
 
 static int rtl8366rb_enable_vlan4k(struct realtek_priv *priv, bool enable)
 {
-	dev_dbg(priv->dev, "%s VLAN 4k\n", enable ? "enable" : "disable");
+	dev_dbg(priv->dev, "%s VLAN 4k\n", str_enable_disable(enable));
 	return regmap_update_bits(priv->map, RTL8366RB_SGCR,
 				  RTL8366RB_SGCR_EN_VLAN_4KTB,
 				  enable ? RTL8366RB_SGCR_EN_VLAN_4KTB : 0);