rtpdec_hevc: Rename a variable for clarity

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec_hevc: Use av_realloc instead of av_malloc+memcpy

Signed-off-by: Martin Storsjö <martin@martin.st>
rtmpproto: Fix a typo

Signed-off-by: Martin Storsjö <martin@martin.st>