drm/i915: Change mutex initialization in intel_guc_log

The intel_guc_log->relay.lock is currently initialized in
intel_guc_log_init_early(), but it lacks a corresponding destructor,
which can lead to a memory leak.

This patch replaces the use of mutex_init() with drmm_mutex_init(),
which ensures the lock is properly destroyed when the driver is
unloaded.

Signed-off-by: Luiz Otavio Mello <luiz.mello@estudante.ufscar.br>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/20250908131518.36625-4-luiz.mello@estudante.ufscar.br
Acked-by: Tvrtko Ursulin <tursulin@ursulin.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: LuizOt31

drivers/gpu/drm/i915/gt/uc/intel_guc_log.c

@@ -6,6 +6,8 @@
 #include <linux/debugfs.h>
 #include <linux/string_helpers.h>
 
+#include <drm/drm_managed.h>
+
 #include "gt/intel_gt.h"
 #include "i915_drv.h"
 #include "i915_irq.h"
@@ -512,7 +514,10 @@ static void guc_log_relay_unmap(struct intel_guc_log *log)
 
 void intel_guc_log_init_early(struct intel_guc_log *log)
 {
-	mutex_init(&log->relay.lock);
+	struct intel_guc *guc = log_to_guc(log);
+	struct drm_i915_private *i915 = guc_to_i915(guc);
+
+	drmm_mutex_init(&i915->drm, &log->relay.lock);
 	INIT_WORK(&log->relay.flush_work, copy_debug_logs_work);
 	log->relay.started = false;
 }