soc: aspeed: lpc-snoop: Rearrange channel paths

soc: aspeed: lpc-snoop: Rearrange channel paths

Order assignments such that tests for conditions not involving resource
acquisition are ordered before those testing acquired resources, and
order managed resource acquisition before unmanaged where possible. This
way we minimise the amount of manual cleanup required.

In the process, improve readability of the code by introducing a channel
pointer that takes the place of the repeated object lookups.

Acked-by: Jean Delvare <jdelvare@suse.de>
Link: https://patch.msgid.link/20250616-aspeed-lpc-snoop-fixes-v2-6-3cdd59c934d3@codeconstruct.com.au
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>