xfstests: resolve compiler warnings
This patch resolves the following compiler/configure warnings:
configure: WARNING: unrecognized options: --enable-lib64
warning: 'xxxx' may be used uninitialized in this function [-Wuninitialized]
warning: variable 'xxx' set but not used [-Wunused-but-set-variable]
warning: call to function 'foo' without a real prototype [-Wunprototyped-calls]
Signed-off-by: Rich Johnston <rjohnston@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>