cpufreq: Use consistent prefixing via pr_fmt

Use the more common kernel style adding a define for pr_fmt.

Miscellanea:

o Remove now unused PFX defines

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/speedstep-lib.c b/drivers/cpufreq/speedstep-lib.c
index 32bdf1d..1b80621 100644
--- a/drivers/cpufreq/speedstep-lib.c
+++ b/drivers/cpufreq/speedstep-lib.c
@@ -8,6 +8,8 @@
  *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
@@ -453,7 +455,7 @@
 		 */
 		if (*transition_latency > 10000000 ||
 		    *transition_latency < 50000) {
-			pr_warn(PFX "frequency transition measured seems out of range (%u nSec), falling back to a safe one of %u nSec\n",
+			pr_warn("frequency transition measured seems out of range (%u nSec), falling back to a safe one of %u nSec\n",
 				*transition_latency, 500000);
 			*transition_latency = 500000;
 		}