[PATCH] Fix bug in rb_write_something() in kernel/trace/ring_buffer.c

With 'make W=1' I get:

  CC      kernel/trace/ring_buffer.o
kernel/trace/ring_buffer.c: In function ‘rb_write_something’:
kernel/trace/ring_buffer.c:4715:6: warning: variable ‘cnt’ set but not used [-Wunused-but-set-variable]
  int cnt;
      ^

The comment before code seems to imply that the local variable should be used, so fix that.

Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Merge branch 'bug_in_ring_buffer' into janitor