scePsmf(): check not initialized status

JPCSP did show that .

ERROR_PSMFPLAYER_NOT_INITIALIZED                    = 0x80616001

00:06:17 movieMainThread - scePsmfPlayerStop 0x927A220 = 0x80616001
00:06:17 movieMainThread - scePsmfPlayerReleasePsmf = 0x80616001

Fixes https://github.com/hrydgard/ppsspp/issues/5437