i40e: Avoid unnecessary use of comma operator

Although it does not seem to have any untoward side-effects,
the use of ';' to separate to assignments seems more appropriate than ','.

Flagged by clang-17 -Wcomma

No functional change intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>