drm/xe/guc: Fix CFI violation in debugfs access.

drm/xe/guc: Fix CFI violation in debugfs access.

xe_guc_print_info is void-returning, but the function pointer it is
assigned to expects an int-returning function, leading to the following
CFI error:

[  206.873690] CFI failure at guc_debugfs_show+0xa1/0xf0 [xe]
(target: xe_guc_print_info+0x0/0x370 [xe]; expected type: 0xbe3bc66a)

Fix this by updating xe_guc_print_info to return an integer.

Fixes: e15826bb3c2c ("drm/xe/guc: Refactor GuC debugfs initialization")
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: George D Sworo <george.d.sworo@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/20260129182547.32899-2-daniele.ceraolospurio@intel.com