[S390] tape: Add pr_fmt() macro to all tape source files

Without defining the pr_fmt() macro, the "tape: " prefix will not be
printed when using the pr_xxx printk macros. This patch adds the
missing definitions.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/tape_std.c b/drivers/s390/char/tape_std.c
index 750354a..03f07e5 100644
--- a/drivers/s390/char/tape_std.c
+++ b/drivers/s390/char/tape_std.c
@@ -11,6 +11,9 @@
  *		 Stefan Bader <shbader@de.ibm.com>
  */
 
+#define KMSG_COMPONENT "tape"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/stddef.h>
 #include <linux/kernel.h>
 #include <linux/bio.h>