MIPS: ftrace: Reword prepare_ftrace_return() comment block

		return;

	/*

	 * "parent_ra_addr" is the stack address saved the return address of

	 * the caller of _mcount.

	 * "parent_ra_addr" is the stack address where the return address of

	 * the caller of _mcount is saved.

	 *

	 * if the gcc < 4.5, a leaf function does not save the return address

	 * in the stack address, so, we "emulate" one in _mcount's stack space,

	 * and hijack it directly, but for a non-leaf function, it save the

	 * return address to the its own stack space, we can not hijack it

	 * directly, but need to find the real stack address,

	 * ftrace_get_parent_addr() does it!

	 * If gcc < 4.5, a leaf function does not save the return address

	 * in the stack address, so we "emulate" one in _mcount's stack space,

	 * and hijack it directly.

	 * For a non-leaf function, it does save the return address to its own

	 * stack space, so we can not hijack it directly, but need to find the

	 * real stack address, which is done by ftrace_get_parent_addr().

	 *

	 * if gcc>= 4.5, with the new -mmcount-ra-address option, for a

	 * If gcc >= 4.5, with the new -mmcount-ra-address option, for a

	 * non-leaf function, the location of the return address will be saved

	 * to $12 for us, and for a leaf function, only put a zero into $12. we

	 * do it in ftrace_graph_caller of mcount.S.

	 * to $12 for us.

	 * For a leaf function, it just puts a zero into $12, so we handle

	 * it in ftrace_graph_caller() of mcount.S.

	 */

	/* old_parent_ra = *parent_ra_addr; */