tests/gem_dummy_reloc_loop: use igt_skip
tests/gem_dummy_reloc_loop: use igt_skip

For tests with subtest we should use igt_skip to ensure that subtests
are always properly enumerated.

Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

chenxianqin/intel-gpu-tools,yipdw/intel-gpu-tools,rib/intel-gpu-tools,dlespiau/checkmate-test-igt,dlespiau/checkmate-test-igt,rib/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,rib/intel-gpu-tools,erikarn/intel-gpu-tools,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,dlespiau/checkmate-test-igt,yipdw/intel-gpu-tools,tiagovignatti/intel-gpu-tools,erikarn/intel-gpu-tools,rib/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools