Not sure if Kernel Version correct
I can see how you'd be confused by that.  It doesn't indicate that your phone is rooted, just that the kernel was compiled by the root user (on a DELL build machine, apparently)!  If you look at /system/build.prop (probably requires root to look, ha) you'll see some other similar information about the build.  Mine says "jaeyoon.yoon@SEP-05" for the same info.