[Piglit] subtests overwriting one another in results file?

[Ilia Mirkin]

Dylan, looks like with your latest json-ification changes:

$ bin/arb_viewport_array-bounds -fbo -auto
Mesa: User error: GL_INVALID_VALUE in glViewportArrayv: index (0)
width or height < 0 (-10.300000, 0.000000)
Mesa: User error: GL_INVALID_VALUE in glViewportIndexedf: index (1)
width or height < 0 (-10.300000, 0.000000)
Mesa: User error: GL_INVALID_VALUE in glViewportIndexedfv: index (2)
width or height < 0 (-10.300000, 0.000000)
Mesa: User error: GL_INVALID_VALUE in glViewportArrayv: index (0)
width or height < 0 (5.000000, -12345.700195)
Mesa: User error: GL_INVALID_VALUE in glViewportIndexedf: index (1)
width or height < 0 (5.000000, -12345.700195)
Mesa: User error: GL_INVALID_VALUE in glViewportIndexedfv: index (2)
width or height < 0 (5.000000, -12345.700195)
PIGLIT: {"subtest": {"Viewport x, y, width, height validity" : "pass"}}
PIGLIT: {"subtest": {"DepthRange near, far validity" : "pass"}}
Mesa: User error: GL_INVALID_VALUE in glScissorArrayv: index (0) width
or height < 0 (-10, 0)
Mesa: User error: GL_INVALID_VALUE in glScissorIndexd: index (1) width
or height < 0 (-10, 0)
Mesa: User error: GL_INVALID_VALUE in glScissorIndexdv: index (2)
width or height < 0 (-10, 0)
Mesa: User error: GL_INVALID_VALUE in glScissorArrayv: index (0) width
or height < 0 (5, -12345)
Mesa: User error: GL_INVALID_VALUE in glScissorIndexd: index (1) width
or height < 0 (5, -12345)
Mesa: User error: GL_INVALID_VALUE in glScissorIndexdv: index (2)
width or height < 0 (5, -12345)
PIGLIT: {"subtest": {"Scissor left, bottom, width, height validity" : "pass"}}
PIGLIT: {"result": "pass" }

Results in

            "subtest": {
                "Scissor left, bottom, width, height validity": "pass"
            },

being recorded in the results.json file. Probably because it is the
last one, and we are just using dict.update directly on the "overall"
dict, but I didn't look at the code carefully.

  -ilia