phy: realtek: usb: Drop unnecessary error check for debugfs_create_dir()

Both debugfs_create_dir() and debugfs_create_file() return ERR_PTR
and never return NULL.

As Greg suggested, this patch removes the error checking for
debugfs_create_dir in phy-rtk-usb2.c and phy-rtk-usb3.c. This is because
the DebugFS kernel API is developed in a way that the caller can safely
ignore the errors that occur during the creation of DebugFS nodes. The
debugfs APIs have a IS_ERR() judge in start_creating() which can handle it
gracefully. So these checks are unnecessary.

Fixes: 134e6d25f6bd ("phy: realtek: usb: Add driver for the Realtek SoC USB 2.0 PHY")
Fixes: adda6e82a7de ("phy: realtek: usb: Add driver for the Realtek SoC USB 3.0 PHY")
Signed-off-by: Jinjie Ruan <[e-mail]>
Suggested-by: Greg Kroah-Hartman <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/realtek/phy-rtk-usb2.c

···
 
 	rtk_phy->debug_dir = debugfs_create_dir(dev_name(rtk_phy->dev),
 						phy_debug_root);
-	if (!rtk_phy->debug_dir)
-		return;
 
-	if (!debugfs_create_file("parameter", 0444, rtk_phy->debug_dir, rtk_phy,
-				 &rtk_usb2_parameter_fops))
-		goto file_error;
+	debugfs_create_file("parameter", 0444, rtk_phy->debug_dir, rtk_phy,
+			    &rtk_usb2_parameter_fops);
 
 	return;
-
-file_error:
-	debugfs_remove_recursive(rtk_phy->debug_dir);
 }
 
 static inline void remove_debug_files(struct rtk_phy *rtk_phy)

drivers/phy/realtek/phy-rtk-usb3.c

···
 		return;
 
 	rtk_phy->debug_dir = debugfs_create_dir(dev_name(rtk_phy->dev), phy_debug_root);
-	if (!rtk_phy->debug_dir)
-		return;
 
-	if (!debugfs_create_file("parameter", 0444, rtk_phy->debug_dir, rtk_phy,
-				 &rtk_usb3_parameter_fops))
-		goto file_error;
+	debugfs_create_file("parameter", 0444, rtk_phy->debug_dir, rtk_phy,
+			    &rtk_usb3_parameter_fops);
 
 	return;
-
-file_error:
-	debugfs_remove_recursive(rtk_phy->debug_dir);
 }
 
 static inline void remove_debug_files(struct rtk_phy *rtk_phy)