Define pr_fmt everywhere.
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>  (powerpc build error)
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Changelog:
Previous pr_fmt definition was too late and caused problems in powerpc
allyesconfg build.