bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
        wrong variable was used as a result of inattentive copypaste.

per-file comments:
  mysql-test/r/gis-precise.result
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     test result updated.

  mysql-test/t/gis-precise.test
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     test case added.

  sql/item_geofunc.cc
bug 839318 Crash in Gcalc_scan_iterator::point::get_shape with ST_DISTANCE and MULTILINESTRING in maria-5.3-gis.
     use 'ev' variable instead of the 'evpos'.