locking/atomic: scripts: split pfx/name/sfx/order

locking/atomic: scripts: split pfx/name/sfx/order

Currently gen-atomic-long.sh's gen_proto_order_variant() function
combines the pfx/name/sfx/order variables immediately, unlike other
functions in gen-atomic-*.sh.

This is fine today, but subsequent patches will require the individual
individual pfx/name/sfx/order variables within gen-atomic-long.sh's
gen_proto_order_variant() function. In preparation for this, split the
variables in the style of other gen-atomic-*.sh scripts.

This results in no change to the generated headers, so there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230605070124.3741859-22-mark.rutland@arm.com