ACPICA: Fix possible memory leak in acpi_ns_get_external_pathname

Fixes a memory leak in the error exit path.
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/namespace/nsnames.c

@@ -142,7 +142,7 @@ char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
 
 	size = acpi_ns_get_pathname_length(node);
 	if (!size) {
-		return (NULL);
+		return_PTR(NULL);
 	}
 
 	/* Allocate a buffer to be returned to caller */
@@ -157,7 +157,8 @@ char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
 
 	status = acpi_ns_build_external_path(node, size, name_buffer);
 	if (ACPI_FAILURE(status)) {
-		return (NULL);
+		ACPI_FREE(name_buffer);
+		return_PTR(NULL);
 	}
 
 	return_PTR(name_buffer);