mtd: elm: Use correct check on return value of pm_runtime_get_sync
mtd: elm: Use correct check on return value of pm_runtime_get_sync

The ELM driver incorrectly reagard any non-zero return value from
pm_runtime_get_sync as an error, but it may return 1 if the device
was already active. Fix to only error when return value is negative.

Signed-off-by: Stefan Sørensen <1a804f3d92b7c6427820dbe6ae21687667b8dec4@spectralink.com>
Signed-off-by: Brian Norris <ac73eed4b8a8c9127255a2696c52b2e7503720b8@gmail.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs