common: cosmetic: CONFIG_BOOTFILE checkpatch compliance

Remove MK_STR from places that consume CONFIG_BOOTFILE to force all definitions to be string literals.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/env_common.c b/common/env_common.c
index 596af82..c7e9bea 100644
--- a/common/env_common.c
+++ b/common/env_common.c
@@ -112,7 +112,7 @@
 	"hostname="	MK_STR(CONFIG_HOSTNAME)		"\0"
 #endif
 #ifdef	CONFIG_BOOTFILE
-	"bootfile="	MK_STR(CONFIG_BOOTFILE)		"\0"
+	"bootfile="	CONFIG_BOOTFILE			"\0"
 #endif
 #ifdef	CONFIG_LOADADDR
 	"loadaddr="	MK_STR(CONFIG_LOADADDR)		"\0"