drm/i915: Fix memory leak by correcting cache object name in error handler

Replace "slab_priorities" with "slab_dependencies" in the error handler
to avoid memory leak.

Fixes: 32eb6bcf ("drm/i915: Make request allocation caches global")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@outlook.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241127201042.29620-1-jiashengjiangcool@gmail.com