nalreader: m_next should equal to m_end when read whole
nalreader: m_next should equal to m_end when read whole

As reading whole buffer, m_next should equal to m_end after finishing
the operation.

Signed-off-by: wudping <eada3ae4a96a673269eca90300aaefadacf3db15@intel.com>

stripes416/libyami,01org/libyami,YuJiankang/libyami,YuJiankang/libyami,stripes416/libyami,lizhong1008/libyami,01org/libyami,lizhong1008/libyami,YuJiankang/libyami,01org/libyami,lizhong1008/libyami,stripes416/libyami