ixgbe: remove whitespace in function comments

Remove unnecessary extra whitespace on all function comments, replacing
' * ' with ' * '.

This was done automatically via sed using the following transformation:

sed 's/^ \*  / * /'

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 (40023f73c76579e58a859dab87b4c30278eb2e48)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D31621