Revert "Fix argument passing in mi_run_cmd_full"

Revert "Fix argument passing in mi_run_cmd_full"

This reverts commit 8c217a4b684386aa5ce6a078dffbe63265a524e6.

Following this

https://sourceware.org/ml/gdb-patches/2014-05/msg00462.html

I suggest reverting my previous commit. I will follow with another
patch to add comments, to clarify some things as stated in the mail
thread.

I ran make check with on gdb.mi, and the test that the commit broke
passes again.

gdb/testsuite/ChangeLog:

2014-05-21  Simon Marchi  <simon.marchi@ericsson.com>

	* lib/mi-support.exp (mi_run_cmd_full): Revert to original
	behavior for $args, pass it directly to "run".