msm: mdss: fb: null check mfd data
msm: mdss: fb: null check mfd data

Add appropriate null check for mfd data
structure before accessing it's members. This
prevents null pointer accesses in the driver.

Change-Id: Id301d4a90c9a52049944c7e3b31aa1a34ad292d7
CRs-Fixed: 526286
Signed-off-by: Manoj Rao <8e3d629b389a351bc9ec544515e25783a6118870@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas