msm: wfd: Return proper error if mmap fails
msm: wfd: Return proper error if mmap fails

Change amends the check condition for mmap return
values appropriately to fix the allocate buffer
failure cases.

CRs-Fixed: 453057
Change-Id: I05ceb4f2960c26e4bc024e0c5f530f874c90a048
Signed-off-by: Rajeshwar Kurapaty <7a65172cf558e1657cd5af14eb34dde18988135b@codeaurora.org>
Signed-off-by: Deva Ramasubramanian <8f8b6109cd5e7b75746932bf5dcf69e763e1f0b2@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