generic/746: clean up fs support

Use a single case statement for fs-specific options and to check if
this test is supported at all.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>
1 file changed