ixgbe: Convert ret val type from s32 to int

Currently big amount of the functions returning standard error codes
are of type s32. Convert them to regular ints as typdefs here are not
necessary to return standard error codes.

Fix incorrect args alignment in touched functions.

Suggested-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.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>