hp-wmi: add return value checking for input_allocate_device()

Add error checking and return -ENOMEM if input_allocate_device() fail.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Thomas Renninger <trenn@suse.de>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/hp-wmi.c

@@ -527,6 +527,8 @@ static int __init hp_wmi_input_setup(void)
 	int err;
 
 	hp_wmi_input_dev = input_allocate_device();
+	if (!hp_wmi_input_dev)
+		return -ENOMEM;
 
 	hp_wmi_input_dev->name = "HP WMI hotkeys";
 	hp_wmi_input_dev->phys = "wmi/input0";