soundwire: fix trailing line in sysfs_slave.c
Commit bcac59029955 ("soundwire: add Slave sysfs support") added
trailing line in file sysfs_slave.c, so remove it
Fixes: bcac59029955 ("soundwire: add Slave sysfs support")
Signed-off-by: Vinod Koul <vkoul@kernel.org>