ixgbe: cleanup spelling mistakes in comments

Several functions in the driver code have a weird function comment
formatting which uses two spaces instead of only one space for the main
function body.

This formatting will be mechanically fixed by sed in a future patch, but
doing so leads to some spelling warnings on that patch. Cleanup the
spelling mistakes that will be detected first. This way, it is easier to
verify the mechanical transformation done by sed in the following patch.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Guinan Sun <guinanx.sun@intel.com>
Reviewed-by: Wei Zhao <wei.zhao1@intel.com>

Approved by: imp
Obtained from: DPDK (fc75eee32037c1379e77e57031c1c353badd2272)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D31621

(cherry picked from commit 46981e903cf3e8e4a5bf7f6152f8ca5b92b37e07)