MIPS: Reindent R6 RI exception emulation

Fold a nested `if' statement for the R6 case in `do_ri' into its
containing `if' block, removing excessive indentation causing code to
extend beyond 79 columns.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9679/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>