exit_player() was declared with differing parameter types in mplayer.c and
mplayer.h. Make the declaration in the .h file match the one in the .c file
and adjust all usages of exit_player() throughout the codebase. Also move
the exit_player() declaration into mp_core.h next to exit_player_with_rc().
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@30558 b3059339-0415-0410-9bf9-f77b7e298cf2