glapi: Remove all offset tags from the XML

glapi: Remove all offset tags from the XML

Changes generated by:

    cd src/mapi/glapi/gen
    for i in *.xml; do
        cat $i |\
        sed 's/[[:space:]]*offset="[^"]*">/>/' |\
        sed 's/[[:space:]]*offset="[^"]*"[[:space:]]*$//' |\
        sed 's/[[:space:]]*offset="[^"]*"[[:space:]]*/ /' > x
        mv x $i
    done

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>