e1000e: cleanup goto statements to exit points without common work

Per ./Documentation/CodingStyle, goto statements are acceptable for the
centralized exiting of functions when there are multiple exit points which
share common work such as cleanup.  When no common work is required for
multiple exit points, the function should just return at these exit points
instead of doing an unnecessary jump to a centralized return.  This patch
cleans up the inappropriate use of goto statements, and removes unnecessary
variables (or move to a smaller scope) where possible as a result of the
cleanups.

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>