general: Fix usage of @float

makeinfo chokes on that.
Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

doc/general.texi

@@ -130,7 +130,7 @@ Go to @url{http://x265.org/developers.html} and follow the instructions
 for installing the library. Then pass @code{--enable-libx265} to configure
 to enable it.
 
-@float note
+@float NOTE
 x265 is under the GNU Public License Version 2 or later
 (see @url{http://www.gnu.org/licenses/old-licenses/gpl-2.0.html} for
 details), you must upgrade FFmpeg's license to GPL in order to use it.