Fix error found by new clang operator precendence warning

[arichardson]

Summary

error: operator '?:' has lower precedence than '|'; '|' will be evaluated first

I discovered this in CheriBSD after updating our fork of clang to the latest
upstream master.

head/usr.sbin/i2c/i2c.c

i2c_rdwr_transfer(char *dev, struct options i2c_opt, char *i2c_buf)
         /*
          * If the transfer direction is write and we did a write of the offset
          * above, then we need to elide the start; this transfer is just more
          * writing that follows the one started above.  For a read, we always do
          * a start; if we did an offset write above it'll be a repeat-start
          * because of the NOSTOP flag used above.
          */
         if (i2c_opt.dir == 'w')
-                msgs[i].flags = IIC_M_WR | (i > 0) ? IIC_M_NOSTART : 0;
+                msgs[i].flags = IIC_M_WR | ((i > 0) ? IIC_M_NOSTART : 0);
         else
                 msgs[i].flags = IIC_M_RD;
         msgs[i].slave = i2c_opt.addr;
         msgs[i].len   = i2c_opt.count;
         msgs[i].buf   = i2c_buf;
         ++i;
 
         xfer.msgs = msgs;