msm: cpufreq: Release cpumask_var_t on all cases

Release cpufreq 'mask' variable when it fails to qualify for changing
cpu frequency.

CRs-fixed: 348827
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
(cherry picked from commit fdf788b79589280622f1fb7f761194234442d2ef)

Change-Id: I38e4de8fee99a68c05df423d19339ba033064eef
Signed-off-by: Zhoulu Luo <zluo@codeaurora.org>