Using linux.Errno as an error doesn't work very well as none of the sentry code
expects error to contain a linux.Errno.
This moves using syserr.Error.ToLinux as an error in a syscall handler from a
runtime error to a compile error.
PiperOrigin-RevId: 227744312
Change-Id: Iea63108a5b198296c908614e09c01733dd684da0