[Intel-gfx] igt: removing the --cmd option from gem_seqno_wrap

[Gore, Tim]

Hi, currently the gem_seqno_wrap test in igt is not built for android due to it
Using the wordexp function which is missing from bionic.
The test author  (Mika Kuoppala) is of the opinion that this option is redundant
And can be removed. Does anyone use this option? Otherwise I'll remove it.

  Tim