ARM: OMAP2+: gpmc: Remove unneeded of_node_put()

for_each_node_by_name() automatically calls of_node_put() on each
node passed; so don't do it explicitly unless there's an error.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>