MIPS: Fix up inconsistency in panic() string argument.

MIPS: Fix up inconsistency in panic() string argument.

Panic() invokes printk() to add a \n internally, so panic arguments should
not themselves end in \n.  Panic invocations in arch/mips and elsewhere
are inconsistently sometimes terminating in \n, sometimes not.

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