misc: rtsx: Remove unneeded return variable

misc: rtsx: Remove unneeded return variable

This patch removes unneeded return variables, using only
'0' instead.
It fixes the following warning detected by coccinelle:
./drivers/misc/cardreader/rtsx_pcr.c:1808:5-8: Unneeded variable: "ret".
Return "0" on line 1833.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/1612164640-84541-1-git-send-email-yang.lee@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>