8361198: [AIX] fix misleading error output in thread_cpu_time_unchecked

Backport-of: 2528c620a61195ac22d921b168444a7967bf1805

Author: MBaesken

src/hotspot/os/aix/os_aix.cpp

@@ -2504,7 +2504,7 @@ static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong*
                           dummy, &dummy_size) == 0) {
     tid = pinfo.__pi_tid;
   } else {
-    tty->print_cr("pthread_getthrds_np failed.");
+    tty->print_cr("pthread_getthrds_np failed, errno: %d.", errno);
     error = true;
   }
 
@@ -2515,7 +2515,7 @@ static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong*
       sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
       user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
     } else {
-      tty->print_cr("pthread_getthrds_np failed.");
+      tty->print_cr("getthrds64 failed, errno: %d.", errno);
       error = true;
     }
   }