staging: vc04_services: no need to check debugfs return values

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Clean up the vchiq_arm code by not caring about the value of debugfs
calls.  This ends up removing a number of lines of code that are not
needed.

Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Keerthi Reddy <keerthigd4990@gmail.com>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>