libgis: include <errno.h> explicitly

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@66396 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/raster/open.c

@@ -19,6 +19,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <errno.h>
 
 #include <grass/config.h>
 #include <grass/gis.h>