aufs: changed to apply local patches thand end with .patch instead of .diff file suffix

This mimics the standard behavior of OpenSDE for normal package builds,
where .patch files found in the $confdir are unconditionally applied,
whereas .diff files are commonly added to the patch file list based on
some conditions defined in the package conf.
aufs: add patch needed when also patching in vserver support into the kernel

The vserver patch changes the type of the 'i_flags' field within 'struct inode'
from 'unsigned int' to 'unsigned short'.