block_Realloc(): cast to block_sys_t after check
block_Realloc(): cast to block_sys_t after check

There are no real functional changes Here. But it is cleaner not to
cast to block_sys_t if the block is not a block_sys_t block (i.e.
was not allocated by block_Alloc()).

jomanmuk/vlc-2.1,vlc-mirror/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.1,xkfz007/vlc,xkfz007/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.1,shyamalschandra/vlc,krichter722/vlc,jomanmuk/vlc-2.1,shyamalschandra/vlc,krichter722/vlc,krichter722/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.1,shyamalschandra/vlc,xkfz007/vlc,jomanmuk/vlc-2.2,krichter722/vlc,vlc-mirror/vlc,vlc-mirror/vlc-2.1,vlc-mirror/vlc,xkfz007/vlc,jomanmuk/vlc-2.1,shyamalschandra/vlc,krichter722/vlc,krichter722/vlc,krichter722/vlc,vlc-mirror/vlc-2.1,shyamalschandra/vlc,jomanmuk/vlc-2.2,shyamalschandra/vlc,xkfz007/vlc,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.2,jomanmuk/vlc-2.1,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,jomanmuk/vlc-2.2,xkfz007/vlc,vlc-mirror/vlc,xkfz007/vlc,vlc-mirror/vlc,vlc-mirror/vlc-2.1,vlc-mirror/vlc-2.1,shyamalschandra/vlc