Change the name of the variable used to detect if we are loading kexts to...

Change the name of the variable used to detect if we are loading kexts to "load-kexts" instead of "disable-kext-loading" since the value is a boolean. This was requested by the person who requested the feature. It now defaults to true:

(lldb) settings show plugin.dynamic-loader.darwin-kernel.load-kexts
plugin.dynamic-loader.darwin-kernel.load-kexts (boolean) = true

llvm-svn: 166315