mtd: nand: omap: drop condition with no effect

The if and the else branch code are identical - so the condition has no
effect on the effective code. This patch removes the condition and the
duplicated code and updates the documentation as suggested by
Roger Quadros <rogerq@ti.com>.

Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Pekon Gupta <pekon@pek-sem.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>