e1000e: cleanup whitespace in recent commit

Commit (c96ddb0b e1000e: Use marco instead of digit for defining
e1000_rx_desc_packet_split) moved a define from one file to another but
missed using proper indentation/whitespace.

CC: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>