bcache-tools: make: permit only one cache device to be specified

Now a cache set only has a single cache, therefore "bcache make" should
permit only one cache device to be specified for a cache set.

This patch checks if more than one cache devices are specified by "-C"
an error message "Please specify only one cache device" will be printed
and bcache exits with usage information.

Signed-off-by: Coly Li <colyli@suse.de>
1 file changed