Revert "ANDROID: GKI: loadavg: Export for get_avenrun"

This reverts commit 64ea6f32.

The symbol get_avenrun is not used by any external modules, so remove
the export as it is useless.  If this is needed, the original commit can
be added back and the symbol added to the relevant symbol list.

Bug: 158067689
Bug: 203756332
Cc: Abhilasha Rao <abhilasha.hv@samsung.corp-partner.google.com>
Cc: Todd Kjos <tkjos@google.com>
Change-Id: I394d074a6cd4afaaf8eb97d528e039bc168e2fe1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>