PM / Runtime: dev_pm_info.runtime_error is signed

dev_pm_info.runtime_error has always been a signed int, to store a signed
error code. Correct the documentation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Runtime: Split line longer than 80 characters

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Runtime: Correct documented return values for generic PM callbacks

As of commit 05aa55dddb9ee4045c320661068bea78dad6a6e5 ("PM / Runtime:
Lenient generic runtime pm callbacks"), the generic power management
callbacks pm_generic_runtime_suspend() and pm_generic_runtime_resume()
return 0, not -EINVAL, if the device doesn't provide its own callbacks.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Runtime: GENERIC_SUBSYS_PM_OPS is gone

Update the documentation for the removal of GENERIC_SUBSYS_PM_OPS in commit
90363ddf0a1a4dccfbb8d0c10b8f488bc7fa69f8 ("PM: Drop generic_subsys_pm_ops")

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Runtime: s/foo_process_requests/foo_process_next_request/

The example uses foo_process_next_request() everywhere else.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PM / Runtime: Spelling s/competing/completing/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>