Fix misspellings of FFmpeg

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/arm/fft_fixed_init_arm.c

@@ -3,7 +3,7 @@
  *
  * This file is part of FFmpeg.
  *
- * FFMpeg is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.

libavcodec/fft-fixed-test.c

 /*
  * This file is part of FFmpeg.
  *
- * FFMpeg is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * FFMpeg is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.

libavfilter/formats.h

 /*
- * This file is part of FFMpeg.
+ * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public