[PATCH 4/6] util/qemu-timer: fix uninitialized variable warning for expire_time

[Chen Qun]

After the WITH_QEMU_LOCK_GUARD macro is added, the compiler cannot identify
 that the statements in the macro must be executed. As a result, some variables
 assignment statements in the macro may be considered as unexecuted by the 
compiler.

The compiler showed warning:
util/qemu-timer.c: In function ‘timerlist_expired’:
util/qemu-timer.c:199:24: warning: ‘expire_time’ may be used uninitialized in 
this function [-Wmaybe-uninitialized]
 199 |     return expire_time <= qemu_clock_get_ns(timer_list->clock->type);
     |            ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/qemu-timer.c: In function ‘timerlist_deadline_ns’:
util/qemu-timer.c:237:11: warning: ‘expire_time’ may be used uninitialized in 
this function [-Wmaybe-uninitialized]
 237 |     delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
     |     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add a default value for 'expire_time' to prevented the warning.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
---
Cc: Paolo Bonzini <pbonzini@redhat.com>
---
 util/qemu-timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 8b73882fbb..3910003e86 100644
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -183,7 +183,7 @@ bool qemu_clock_has_timers(QEMUClockType type)
 
 bool timerlist_expired(QEMUTimerList *timer_list)
 {
-    int64_t expire_time;
+    int64_t expire_time = -1;
 
     if (!qatomic_read(&timer_list->active_timers)) {
         return false;
@@ -213,7 +213,7 @@ bool qemu_clock_expired(QEMUClockType type)
 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
 {
     int64_t delta;
-    int64_t expire_time;
+    int64_t expire_time = -1;
 
     if (!qatomic_read(&timer_list->active_timers)) {
         return -1;
-- 
2.27.0