firmware: arm_scmi: quirk: Simplify quirk table iteration

firmware: arm_scmi: quirk: Simplify quirk table iteration

The current table entry is assigned in both the init and loop
expressions of the for-statement.  Merge this into a single assignment
in the conditional expression, to simplify the code.

While at it, make the loop counter unsigned and loop-local.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/8577f4b103cf04420c3b67dcaad528daff867287.1775205358.git.geert+renesas@glider.be
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>