KVM: selftests: Fix spelling of 'occurrences' in sparsebit.c comments

Correct two instances of the misspelled word 'occurences' to
'occurrences' in comments explaining node invariants in sparsebit.c.

Signed-off-by: Rahul Kumar <rk0006818@gmail.com>
Link: https://lore.kernel.org/r/20250523181606.568320-1-rk0006818@gmail.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: rahul19kumar8

tools/testing/selftests/kvm/lib/sparsebit.c

@@ -116,7 +116,7 @@
  *
  *   + A node with all mask bits set only occurs when the last bit
  *     described by the previous node is not equal to this nodes
- *     starting index - 1.  All such occurences of this condition are
+ *     starting index - 1.  All such occurrences of this condition are
  *     avoided by moving the setting of the nodes mask bits into
  *     the previous nodes num_after setting.
  *
@@ -592,7 +592,7 @@ static struct node *node_split(struct sparsebit *s, sparsebit_idx_t idx)
  *
  *   + A node with all mask bits set only occurs when the last bit
  *     described by the previous node is not equal to this nodes
- *     starting index - 1.  All such occurences of this condition are
+ *     starting index - 1.  All such occurrences of this condition are
  *     avoided by moving the setting of the nodes mask bits into
  *     the previous nodes num_after setting.
  */