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
Change-Id: I90b13aef01f39ee37ae2693fad494c50cb083e27
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>

Conflicts:

	arch/arm/mach-msm/cpufreq.c