dynamic_debug: Remove uses of KERN_CONT in dynamic_emit_prefix

Multiple printks with KERN_CONT can be interleaved by
other printks.  Reduce the likelihood of that interleaving
by consolidating multiple calls to printk.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>