mm/slub: drop duplicate kernel-doc for ksize()

The implementation of ksize() was updated with kernel-doc by commit
fab0694 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
However, the public header still contains a kernel-doc comment
attached to the ksize() prototype.

Having documentation both in the header and next to the implementation
causes Sphinx to treat the function as being documented twice,
resulting in the warning:

  WARNING: Duplicate C declaration, also defined at core-api/mm-api:521
  Declaration is '.. c:function:: size_t ksize(const void *objp)'

Kernel-doc guidelines recommend keeping the documentation with the
function implementation. Therefore remove the redundant kernel-doc
block from include/linux/slab.h so that the implementation in slub.c
remains the canonical source for documentation.

No functional change.

Fixes: fab0694 ("mm/slab: move [__]ksize and slab_ksize() to mm/slub.c")
Signed-off-by: Sanjay Chitroda <sanjayembeddedse@gmail.com>
Link: https://patch.msgid.link/20260226054712.3610744-1-sanjayembedded@gmail.com
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

Author: sanjay-embedded

include/linux/slab.h

@@ -517,18 +517,6 @@ void kfree_sensitive(const void *objp);
 DEFINE_FREE(kfree, void *, if (!IS_ERR_OR_NULL(_T)) kfree(_T))
 DEFINE_FREE(kfree_sensitive, void *, if (_T) kfree_sensitive(_T))
 
-/**
- * ksize - Report actual allocation size of associated object
- *
- * @objp: Pointer returned from a prior kmalloc()-family allocation.
- *
- * This should not be used for writing beyond the originally requested
- * allocation size. Either use krealloc() or round up the allocation size
- * with kmalloc_size_roundup() prior to allocation. If this is used to
- * access beyond the originally requested allocation size, UBSAN_BOUNDS
- * and/or FORTIFY_SOURCE may trip, since they only know about the
- * originally allocated size via the __alloc_size attribute.
- */
 size_t ksize(const void *objp);
 
 #ifdef CONFIG_PRINTK