staging: lustre: Remove typedef and update cfs_debug_limit_state struct

Removed typedef keyword and rename the cfs_debug_limit_state_t
struct to cfs_debug_limit_state in libcfs_debug.h. These changes
resolve the "Do not add new typedefs" warning generated by
checkpatch.pl and meet kernel coding style.

Struct variables in other header and source files
that depend on libcfs_debug.h are updated as well.

Signed-off-by: Lisa Nguyen <lisa@xenapiadmin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>