Add include files to get prototype declarations, and fix bugs found.

Add include files to get prototype declarations, and fix bugs found.

SCCS-vsn: lib/libc/stdio/fdopen.c 5.6
SCCS-vsn: lib/libc/stdio/findfp.c 5.10
SCCS-vsn: lib/libc/stdio/fpurge.c 5.2
SCCS-vsn: lib/libc/stdio/fputs.c 5.6
SCCS-vsn: lib/libc/stdio/freopen.c 5.6
SCCS-vsn: lib/libc/stdio/fseek.c 5.7
SCCS-vsn: lib/libc/stdio/fwalk.c 5.2
SCCS-vsn: lib/libc/stdio/fwrite.c 5.5
SCCS-vsn: lib/libc/stdio/makebuf.c 5.2
SCCS-vsn: lib/libc/stdio/mktemp.c 5.10
SCCS-vsn: lib/libc/stdio/perror.c 5.11
SCCS-vsn: lib/libc/stdio/puts.c 5.6
SCCS-vsn: lib/libc/stdio/refill.c 5.3
SCCS-vsn: lib/libc/stdio/remove.c 5.3
SCCS-vsn: lib/libc/stdio/setbuffer.c 5.4
SCCS-vsn: lib/libc/stdio/stdio.c 5.3
SCCS-vsn: lib/libc/stdio/tmpfile.c 5.3
SCCS-vsn: lib/libc/stdio/tmpnam.c 5.3
SCCS-vsn: lib/libc/stdio/vfprintf.c 5.45
SCCS-vsn: lib/libc/stdio/vfscanf.c 5.6
SCCS-vsn: lib/libc/stdio/vprintf.c 5.6
SCCS-vsn: lib/libc/stdio/wsetup.c 5.2