[PATCH 1/2] kdbus: Fix the overflow for timeout calculation

[PATCH 1/2] kdbus: Fix the overflow for timeout calculation

The maximum value of unsigned long is 4294967295 which is too small
for storing nano second. It makes the overflow in calculation.
Use LLU instead of LU for timeout calculation.
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Subject: [PATCH 2/2] kdbus: adjust the default value for timeout to 50 sec
This definition is used by the default value for timeout value.
But in the other places, 50 sec is used by default value for timeout,
instead of using it.
Let's align it with the others

Signed-off-by: INSUN PYO <insun.pyo@samsung.com>
Change-Id: Idddaf3f095ad47206f8b6ac11bc46c43c3bc8bd3