cgrulesengd: Fixed processing of symlinked executables.

cgrulesengd: Fixed processing of symlinked executables.

when an executable is symlinked and the symlink is executed,
/proc/PID/status contains name of the symlink, while /proc/PID/exe points
to the real executable name. cgrulesengd considered this case as error and
did not trigger any rule for this exec().

With this patch, cgrulesengd uses name of /proc/PID/exe as the executable
in this case.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>