drm/xe/pxp: Clear restart flag in pxp_start after jumping back

If we don't clear the flag we'll keep jumping back at the beginning of
the function once we reach the end.

Fixes: ccd3c68 ("drm/xe/pxp: Decouple queue addition from PXP start")
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Julia Filipchuk <julia.filipchuk@intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patch.msgid.link/20260324153718.3155504-9-daniele.ceraolospurio@intel.com
(cherry picked from commit 0850ec7bb2459602351639dccf7a68a03c9d1ee0)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: dceraolo

drivers/gpu/drm/xe/xe_pxp.c

@@ -512,7 +512,7 @@ static int __exec_queue_add(struct xe_pxp *pxp, struct xe_exec_queue *q)
 static int pxp_start(struct xe_pxp *pxp, u8 type)
 {
 	int ret = 0;
-	bool restart = false;
+	bool restart;
 
 	if (!xe_pxp_is_enabled(pxp))
 		return -ENODEV;
@@ -541,6 +541,8 @@ static int pxp_start(struct xe_pxp *pxp, u8 type)
 					 msecs_to_jiffies(PXP_ACTIVATION_TIMEOUT_MS)))
 		return -ETIMEDOUT;
 
+	restart = false;
+
 	mutex_lock(&pxp->mutex);
 
 	/* If PXP is not already active, turn it on */