bnxt_en: fix format specifier in live patch error message

This fixes type mismatch warning.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3c415339 ("bnxt_en: implement firmware live patching")
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>