ima: Unify logging

Define pr_fmt everywhere.

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

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

security/integrity/ima/ima_template_lib.c

@@ -13,6 +13,8 @@
  *      Library of supported template fields.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include "ima_template_lib.h"
 
 static bool ima_template_hash_algo_allowed(u8 algo)