boot/nxboot/loader/flash.c: open partition with O_DIRECT flag

There is no need to use buffers in a bootloader. We expect a sequential
access, therefore we just need to erase the erase page before writing
to it for the first time, which is something FTL layer already takes
care of.

Signed-off-by: Michal Lenc <[email protected]>

Author: michallenc

boot/nxboot/loader/flash.c

@@ -64,7 +64,7 @@ int flash_partition_open(const char *path)
 {
   int fd;
 
-  fd = open(path, O_RDWR);
+  fd = open(path, O_RDWR | O_DIRECT);
   if (fd < 0)
     {
       syslog(LOG_ERR, "Could not open %s partition: %s\n",