qlibc: unbreak legal-info after version bump

Fixes:
http://autobuild.buildroot.org/results/12f/12f89408935143050a27d92f4b6796d50da07da1/

The recent version bump to v2.4.1 forgot to update the name of the license
file which has been renamed upstream (and reindented/copyright year updated,
but is otherwise identical).

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qlibc/qlibc.mk

@@ -7,7 +7,7 @@
 QLIBC_VERSION = v2.4.1
 QLIBC_SITE = $(call github,wolkykim,qlibc,$(QLIBC_VERSION))
 QLIBC_LICENSE = BSD-2c
-QLIBC_LICENSE_FILES = COPYING
+QLIBC_LICENSE_FILES = LICENSE
 
 # We're patching configure.ac
 QLIBC_AUTORECONF = YES