MIPS: Return after handling coprocessor 2 exception

MIPS: Return after handling coprocessor 2 exception

Breaking here dropped us to the default code which always sends a SIGILL
to the current process, no matter what the CU2 notifier says.

[Ralf: Currently this only hurts on Cavium and possibly some out of tree
platforms.]

Signed-off-by: Jesper Nilsson <jesper@jni.nu>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1391/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>