Fix location of udev files.
Fix location of udev files.

Not all distributions store udev rules files in /lib. Some will for
example store them in /lib64 without a symlink to it from /lib. This
trival patch lets configure discover the location based on what is
passed on the command line.

olunx/libmtp,philipl/libmtp,jemc/libmtp,vmandela/libmtp,reverendhomer/libmtp,jemc/libmtp,libmtp/libmtp,reverendhomer/libmtp,kbhomes/libmtp-zune,reverendhomer/libmtp,pierrezurek/libmtp,olunx/libmtp,jemc/libmtp,jemc/libmtp,philipl/libmtp,Bluerise/libmtp,Bluerise/libmtp,philipl/libmtp,pierrezurek/libmtp,olunx/libmtp,yifanlu/libMTP,vmandela/libmtp,mmalecki/libmtp,kbhomes/libmtp-zune,reverendhomer/libmtp,mmalecki/libmtp,Bluerise/libmtp,libmtp/libmtp,libmtp/libmtp,mmalecki/libmtp,yifanlu/libMTP