uboot-imx

tools: mkimage: Call fclose in error path

This patch is fixing missing fclose() calls
in error patch introduced by:
"tools: mkimage: Use fstat instead of stat to avoid malicious hacks"
(sha1: ebe0f53f48e8f9ecc823e533a85b05c13638c350)

Reported-by: Coverity (CID: 155064, 155065)
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>