power: supply: ab8500_fg: drop duplicated 'is' in comment

Fix word duplication typo 'is is' -> 'is'.

Signed-off-by: Jiang Jian <[e-mail]>
[update commit message]
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/ab8500_fg.c

···
  * ab8500_fg_clear_cap_samples() - Clear average filter
  * @di:		pointer to the ab8500_fg structure
  *
- * The capacity filter is is reset to zero.
+ * The capacity filter is reset to zero.
  */
 static void ab8500_fg_clear_cap_samples(struct ab8500_fg *di)
 {