gpio/ep93xx: fix pr_fmt output

With this driver now being moved from arch/arm/mach-ep93xx/gpio.c to
drivers/gpio/gpio-ep93xx.c the prefix "ep93xx" is now redundant in the
pr_* output. Using KBUILD_MODNAME is sufficient.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpio-ep93xx.c

@@ -11,7 +11,7 @@
  *  published by the Free Software Foundation.
  */
 
-#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/init.h>
 #include <linux/module.h>