scsi: ufs: fix function definition error

In commit 71ce1d94 ("Merge remote-tracking branch
'tmp-44e63be6' into 4.9"), func ufshcd_vops_suspend is
defined wrongly, this fix corrects it.

Change-Id: Id90c5613e66c2f2c22ce59a07af71eb7b3250b15
Signed-off-by: Can Guo <cang@codeaurora.org>