HID: ishtp-hid-client: Fix 'suggest-attribute=format' compiler warning

Fixes the following W=1 kernel build warning(s):

 drivers/hid/intel-ish-hid/ishtp/bus.c: In function ‘ishtp_trace_callback’:
 drivers/hid/intel-ish-hid/ishtp/bus.c:876:29: warning: return type might be a candidate for a format attribute [-Wsuggest-attribute=format]
 876 | return cl_device->ishtp_dev->print_log;
 | ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~

Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Daniel Drubin <daniel.drubin@intel.com>
Cc: linux-input@vger.kernel.org
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/include/linux/intel-ish-client-if.h b/include/linux/intel-ish-client-if.h
index 94669e21dc8b..25e2b4e80502 100644
--- a/include/linux/intel-ish-client-if.h
+++ b/include/linux/intel-ish-client-if.h
@@ -8,11 +8,17 @@
 #ifndef _INTEL_ISH_CLIENT_IF_H_
 #define _INTEL_ISH_CLIENT_IF_H_
 
+#include <linux/device.h>
+#include <linux/uuid.h>
+
 struct ishtp_cl_device;
 struct ishtp_device;
 struct ishtp_cl;
 struct ishtp_fw_client;
 
+typedef __printf(2, 3) void (*ishtp_print_log)(struct ishtp_device *dev,
+					       const char *format, ...);
+
 /* Client state */
 enum cl_state {
 	ISHTP_CL_INITIALIZING = 0,
@@ -76,7 +82,7 @@ int ishtp_register_event_cb(struct ishtp_cl_device *device,
 /* Get the device * from ishtp device instance */
 struct device *ishtp_device(struct ishtp_cl_device *cl_device);
 /* Trace interface for clients */
-void *ishtp_trace_callback(struct ishtp_cl_device *cl_device);
+ishtp_print_log ishtp_trace_callback(struct ishtp_cl_device *cl_device);
 /* Get device pointer of PCI device for DMA acces */
 struct device *ishtp_get_pci_device(struct ishtp_cl_device *cl_device);