[PATCH] backlight: fix oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/*
[PATCH] backlight: fix oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/*

Seems like not all drivers use the framebuffer_alloc() function and won't
have an initialized mutex.  But those don't have a backlight, anyway.

Signed-off-by: Michael Hanselmann <2578944098299abf708b08eff6fcf60565553586@hansmi.ch>
Cc: Olaf Hering <ded022db89399a060a39da31922f173c6556c2d9@aepfle.de>
Cc: "Antonino A. Daplas" <be03a811842969f6b435f66cb85a30eb479a8702@pol.net>
Cc: Daniel R Thompson <4421c302a8f2019ff02452a16ddbdd37770f814c@st.com>
Cc: Jon Smirl <4834b08ab1b46972472cae1b58758b8c600e5e2b@gmail.com>
Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@kernel.org>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@osdl.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@osdl.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs