babeld: fix typo in variable name

As pointed out during the check-package discussion, there is a typo in a
variable name:

http://lists.busybox.net/pipermail/buildroot/2016-December/180765.html

Fixing that also shows that the license file was misspelled, so fix that as
well (LICENSE/LICENCE).

Reported-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/babeld/babeld.mk

@@ -6,8 +6,8 @@
 
 BABELD_VERSION = 1.7.1
 BABELD_SITE = http://www.pps.univ-paris-diderot.fr/~jch/software/files
-BALELD_LICENSE = MIT
-BALELD_LICENSE_FILES = LICENSE
+BABELD_LICENSE = MIT
+BABELD_LICENSE_FILES = LICENCE
 
 define BABELD_BUILD_CMDS
 	$(MAKE) -C $(@D) $(TARGET_CONFIGURE_OPTS)