audio-hal: fix for kw issue

Changes to fix file descriptor close.

Change-Id: Icff466d1f758190b9aa77b72d6896a664df3ebce
diff --git a/hal/audio_extn/spkr_protection.c b/hal/audio_extn/spkr_protection.c
index 418707b..571b4f3 100644
--- a/hal/audio_extn/spkr_protection.c
+++ b/hal/audio_extn/spkr_protection.c
@@ -1877,7 +1877,7 @@
     if (ioctl(cal_fd, AUDIO_SET_CALIBRATION, &cal_data))
         ALOGE("%s: failed to set TH VI V_VALI_CFG, errno = %d", __func__, errno);
 
-    if (cal_fd > 0)
+    if (cal_fd >= 0)
         close(cal_fd);
 done:
     return ret;