At some point, pr_warning will be removed so all logging messages use
a consistent <prefix>_warn style.

Update arch/powerpc/

Miscellanea:

o Coalesce formats
o Realign arguments
o Use %s, __func__ instead of embedded function names
o Remove unnecessary line continuations
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NGeoff Levand <geoff@infradead.org>
[mpe: Rebase due to some %pOF changes.]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>