Input: iqs269a - drop unused device node references

Each call to device/fwnode_get_named_child_node() must be matched
with a call to fwnode_handle_put() once the corresponding node is
no longer in use. This ensures a reference count remains balanced
in the case of dynamic device tree support.

Currently, the driver does not call fwnode_handle_put() on nested
event nodes. This patch solves this problem by adding the missing
instances of fwnode_handle_put().

As part of this change, the logic which parses each channel's key
code is gently refactored in order to reduce the number of places
from which fwnode_handle_put() is called.

Fixes: 04e49867 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/Y7Rsx68k/gvDVXAt@nixie71Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/iqs269a.c

@@ -694,6 +694,7 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
 				dev_err(&client->dev,
 					"Invalid channel %u threshold: %u\n",
 					reg, val);
+				fwnode_handle_put(ev_node);
 				return -EINVAL;
 			}
 
@@ -707,6 +708,7 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
 				dev_err(&client->dev,
 					"Invalid channel %u hysteresis: %u\n",
 					reg, val);
+				fwnode_handle_put(ev_node);
 				return -EINVAL;
 			}
 
@@ -721,8 +723,16 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
 			}
 		}
 
-		if (fwnode_property_read_u32(ev_node, "linux,code", &val))
+		error = fwnode_property_read_u32(ev_node, "linux,code", &val);
+		fwnode_handle_put(ev_node);
+		if (error == -EINVAL) {
 			continue;
+		} else if (error) {
+			dev_err(&client->dev,
+				"Failed to read channel %u code: %d\n", reg,
+				error);
+			return error;
+		}
 
 		switch (reg) {
 		case IQS269_CHx_HALL_ACTIVE: