scsi: ufs: Fix missing brace warning for old compilers

scsi: ufs: Fix missing brace warning for old compilers

For older versions of gcc, the array = {0}; will cause warnings:

drivers/scsi/ufs/ufshcd-crypto.c: In function 'ufshcd_crypto_keyslot_program':
drivers/scsi/ufs/ufshcd-crypto.c:62:8: warning: missing braces around initializer [-Wmissing-braces]
  union ufs_crypto_cfg_entry cfg = { 0 };
        ^
drivers/scsi/ufs/ufshcd-crypto.c:62:8: warning: (near initialization for 'cfg.reg_val') [-Wmissing-braces]
drivers/scsi/ufs/ufshcd-crypto.c: In function 'ufshcd_clear_keyslot':
drivers/scsi/ufs/ufshcd-crypto.c:103:8: warning: missing braces around initializer [-Wmissing-braces]
  union ufs_crypto_cfg_entry cfg = { 0 };
        ^
2 warnings generated

Link: https://lore.kernel.org/r/20201002063538.1250-1-shipujin.t@gmail.com
Fixes: 70297a8ac7a7 ("scsi: ufs: UFS crypto API")
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>