tests/gem_wait: Don't close drmfd in subtest
tests/gem_wait: Don't close drmfd in subtest

I didn't notice this on the machine I developed it since the original
wait testcase fails there. Oops.

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

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