wayland: Don't check *alloc result
wayland: Clean up anonymous file creation

It was a copy paste without fully updating the coding style. There were
also some autotools macros that were no longer valid. So far its assumed
that the needed functions exist. If better portability is needed, there
needs to be some detction added to the cmake build script.
wayland: Default to 32 cursor image size

This is the default across various toolkits (weston, GTK+ for example)
so lets stick to that.
wayland: Coding style cleanup

Fixes * positioning, indentation and newline inconsistencies.