lib/rhashtable: fix comment on locks_mul default value

As of commit 4cf0b354d92 ("rhashtable: avoid large lock-array
allocations"), the default value for the locks multiplier was reduced
from 128 to 32.

Update the header file to reflect this.

Link: http://lkml.kernel.org/r/20170815215401.30745-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/rhashtable.h

@@ -127,7 +127,7 @@ struct rhashtable;
  * @head_offset: Offset of rhash_head in struct to be hashed
  * @max_size: Maximum size while expanding
  * @min_size: Minimum size while shrinking
- * @locks_mul: Number of bucket locks to allocate per cpu (default: 128)
+ * @locks_mul: Number of bucket locks to allocate per cpu (default: 32)
  * @automatic_shrinking: Enable automatic shrinking of tables
  * @nulls_base: Base value to generate nulls marker
  * @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)