sm8350-common: gpt-utils: Do fsync after writing partition entries

Do fsync after writing partition entries to ensure data
is actually written before rebooting device.

Change-Id: I09659cab247fe280dc608e30a88d912034cbc01a

gpt-utils/gpt-utils.cpp

@@ -1478,7 +1478,7 @@ int gpt_disk_commit(struct gpt_disk *disk)
                 ALOGE("%s: Invalid args", __func__);
                 goto error;
         }
-        fd = open(disk->devpath, O_RDWR);
+        fd = open(disk->devpath, O_RDWR | O_DSYNC);
         if (fd < 0) {
                 ALOGE("%s: Failed to open %s: %s",
                                 __func__,
@@ -1510,6 +1510,7 @@ int gpt_disk_commit(struct gpt_disk *disk)
                                 __func__);
                 goto error;
         }
+        fsync(fd);
         close(fd);
         return 0;
 error: