firmware: qcom: uefisecapp: Simplify mutex with guard

Simplify error path unlocking mutex with the guard.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260216091525.107935-4-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: krzk

drivers/firmware/qcom/qcom_qseecom_uefisecapp.c

@@ -699,16 +699,13 @@ static DEFINE_MUTEX(__qcuefi_lock);
 
 static int qcuefi_set_reference(struct qcuefi_client *qcuefi)
 {
-	mutex_lock(&__qcuefi_lock);
+	guard(mutex)(&__qcuefi_lock);
 
-	if (qcuefi && __qcuefi) {
-		mutex_unlock(&__qcuefi_lock);
+	if (qcuefi && __qcuefi)
 		return -EEXIST;
-	}
 
 	__qcuefi = qcuefi;
 
-	mutex_unlock(&__qcuefi_lock);
 	return 0;
 }