firmware: define pr_fmt

For some reason we have always forgotten this. Without this
we don't get a nice prefix on our pr_debug() / pr_*() messages.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_class.c

@@ -7,6 +7,8 @@
  *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/capability.h>
 #include <linux/device.h>
 #include <linux/module.h>