uboot-phytec

mmc: tmio: Improve error handling

Properly handle return values and abort operations when they are
non-zero. This is a minor improvement, which fixes two remaining
unchecked return values.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>