drm/i915/vma: fix kernel-doc function name for i915_vma_size()

drivers/gpu/drm/i915/i915_vma.h:145: warning: expecting prototype for i915_vma_offset(). Prototype was for i915_vma_size() instead
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9fd58398ba6f86c55cc7a7c62efeab70c3311d59.1683041799.git.jani.nikula@intel.com

drivers/gpu/drm/i915/i915_vma.h

@@ -132,7 +132,7 @@ static inline u64 __i915_vma_size(const struct i915_vma *vma)
 }
 
 /**
- * i915_vma_offset - Obtain the va range size of the vma
+ * i915_vma_size - Obtain the va range size of the vma
  * @vma: The vma
  *
  * GPU virtual address space may be allocated with padding. This