Partially revert recent H8 patch for conditional branches

So I'd forgotten an important tidbit on the H8 port.  Specifically
for a branch instruction, the target label must be operand 0 for
the length computations.

This really only affects the main conditional branch pattern.
The other conditional branch patterns are split and ultimately
funnel into the main pattern.  This patch fixes the issue by
partially reverting an earlier change.  This issue didn't show up
until late in the optimization work on cc0 removal of the H8 port,
but was caught by the testsuite.  So there's no new test.

Built and regression tested H8 with this change, with and without
the cc0 removal patches.

gcc/

	* config/h8300/jumpcall.md (branch_true, branch_false): Revert
	recent change.  Ensure operand[0] is always the target label.