drm/arm/komeda: don't use confusing 'timeout' variable name

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Check the return value directly to drop
'timeout'  which also fixes its wrong type.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240507090200.7936-2-wsa+renesas@sang-engineering.com
[changed commit title to match driver name]
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>