avtimer: fix uninitialized variable compilation warning

Fix the following compilation warning in the avtimer driver:

kernel/drivers/platform/msm/avtimer.c:
	In function 'dev_avtimer_probe':
kernel/drivers/platform/msm/avtimer.c:316:
	warning: 'result' may be used uninitialized in this function
error, forbidden warning: avtimer.c:316
make[5]: *** [drivers/platform/msm/avtimer.o] Error 1

Change-Id: Ia760ba174e36bbcd63ed1c18cfcdce4308c825e1
Signed-off-by: David Collins <collinsd@codeaurora.org>