drivers/misc/ocxl: remove redundant rc variable

Return value from ocxl_context_attach() directly instead
of taking this in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Link: https://lore.kernel.org/r/20211215060438.441918-1-chi.minghao@zte.com.cn


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>