Fix GCC build breaks.

Fix GCC build breaks.
Fix case mismatch for includes of "Socket.h".  Original code was <socket.h> while file was Socket.h in the same directory as the .c file.
Add EFIAPI to function declarations so that they match the definition.
Remove "ineffective" statements from stub functions.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12076 6f19259b-4bc3-4df7-8a09-765794883524