filelock: fix name of file_lease slab cache

When struct file_lease was split out from struct file_lock, the name of
the file_lock slab cache was copied to the new slab cache for
file_lease. This name conflict causes confusion in /proc/slabinfo and
/sys/kernel/slab. In particular, it caused failures in drgn's test case
for slab cache merging.

Link: https://github.com/osandov/drgn/blob/9ad29fd86499eb32847473e928b6540872d3d59a/tests/linux_kernel/helpers/test_slab.py#L81


Fixes: c69ff407 ("filelock: split leases out of struct file_lock")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/r/2d1d053da1cafb3e7940c4f25952da4f0af34e38.1722293276.git.osandov@fb.com


Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>