Successfully read kernel versions with only 2 components

When the kernel version as stated in /proc/version did not have at least
three numbers separated by periods, the version would fail to be read.
Sample /proc/version to demonstrate problem:

    Linux version 3.10-3-686-pae ...

The Linux kernel will always have a major number and a minor number
separated by a period.  There is likely also a patch version number too
that would be preceded by a period.  This enhancement will read 2 and 3
component Linux kernel versions.