exempi: fix comment entry quote

Fixes the following warning:
package/exempi/Config.in:14:warning: multi-line strings not supported

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

package/exempi/Config.in

@@ -11,5 +11,5 @@ config BR2_PACKAGE_EXEMPI
 
 	  http://libopenraw.freedesktop.org/wiki/Exempi
 
-comment "exempi needs a toolchain w/ C++, dynamic library, threads
+comment "exempi needs a toolchain w/ C++, dynamic library, threads"
 	depends on BR2_STATIC_LIBS || !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS