package/glslsandbox-player: fix build with libexecinfo

Fix build failure raised on uclibc and musl since the addition of
libexecinfo package in commit:
eea8ba446c10701a273432552108d80fb2224ef4

Fixes:
- http://autobuild.buildroot.net/results/9591ffe5968fe5f20b29799d1c234426cacd549a

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 99113727d6458fff1aaae7f9e9305f9b657d4263)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/glslsandbox-player/glslsandbox-player.mk

@@ -12,6 +12,11 @@ GLSLSANDBOX_PLAYER_DEPENDENCIES = libegl libgles host-pkgconf
 GLSLSANDBOX_PLAYER_LICENSE = BSD-2-Clause
 GLSLSANDBOX_PLAYER_LICENSE_FILES = LICENSE
 
+ifeq ($(BR2_PACKAGE_LIBEXECINFO),y)
+GLSLSANDBOX_PLAYER_DEPENDENCIES += libexecinfo
+GLSLSANDBOX_PLAYER_CONF_ENV += LIBS="-lexecinfo"
+endif
+
 ifeq ($(BR2_PACKAGE_GLSLSANDBOX_PLAYER_PNG),y)
 GLSLSANDBOX_PLAYER_DEPENDENCIES += libpng
 GLSLSANDBOX_PLAYER_CONF_OPTS += --with-libpng