usb: Check return value of umount ffs

Check return value of umount usb ffs to remove unchecked return
value.

Change-Id: Ib4016046783a7724612baee9a158c922da0e9f3e
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

diff --git a/src/usb.c b/src/usb.c
index 03bcada..6eae41a 100644 (file)
--- a/src/usb.c
+++ b/src/usb.c
@@ -396,7 +396,12 @@ static int mount_ffs(void)
 
 static void umount_ffs(void)
 {
-       umount(TFMFFS_PATH);
+       int ret;
+
+       ret = umount(TFMFFS_PATH);
+       if (ret < 0)
+               fprintf(stderr, "Failed to unmount usb ffs\n");
+
        rmdir(TFMFFS_PATH);
 }