vold: Do not print fstrim amount if ioctl returns an error

Change-Id: I8620ea67a774ead51bd6bd9b6e737bf3d634470b
diff --git a/fstrim.c b/fstrim.c
index 1ffd312..efee800 100644
--- a/fstrim.c
+++ b/fstrim.c
@@ -76,8 +76,9 @@
         if (ioctl(fd, FITRIM, &range)) {
             SLOGE("FITRIM ioctl failed on %s", fstab->recs[i].mount_point);
             ret = -1;
+        } else {
+            SLOGI("Trimmed %llu bytes on %s\n", range.len, fstab->recs[i].mount_point);
         }
-        SLOGI("Trimmed %llu bytes on %s\n", range.len, fstab->recs[i].mount_point);
         close(fd);
     }
     SLOGI("Finished fstrim work.\n");